Daikin Installation Instructions

WARNING

Only personnel trained to install, adjust, service, or repair the equipment should do so. The manufacturer is not responsible for injury or property damage from improper service. Improper installation, adjustment, servicing, or repair may result in product damage, property damage, personal injury, or death.

This forced air central unit complies with American National Standard/National Standard of Canada ANSI Z21.47-CSA-2.3 Gas-fired central furnaces.

Our continuing commitment to quality products may mean a change in specifications without notice.

© 2020-2021 DAIKIN MANUFACTURING COMPANY, L.P.
19001 Kermier Rd., Waller, TX 77484
www.daikincomfort.com

INDEX

• Replacement Parts
• Safety Instructions
• General Information
• Clearances
• Roof Curb Post-Installation Checks
• Roof Top Duct Connections
• Rigging Details
• Weights and Center of Gravity
• Electrical Wiring
• Gas Supply Piping
• Circulating Air and Filters
• Condensate Drain Connection
• Startup, Adjustments, and Checks
• Air Flow Adjustments
• Gas System Check
• Normal Sequence of Operation
• Maintenance
• Troubleshooting
• Appendix A Blower Performance Data
• Appendix B Electrical Data
• Appendix C Unit Dimensions
• Appendix D Min-Max Airflow
• Wiring Diagrams
• Startup Checklist

REPLACEMENT PARTS

Ordering Parts

When reporting shortages or damages, or ordering repair parts, provide the complete unit model and serial numbers as stamped on the unit's nameplate.

Replacement parts are available through your contractor or local distributor. Find your local distributor at www.daikinac.com or contact:

EQUIPMENT SUPPORT

Daikin North America LLC
19001 Kermier Road
Waller, Texas 77484
855-770-5678

SAFETY INSTRUCTIONS

Recognize this symbol as a safety precaution: ⚠️

To The Installer

Before installing this unit, read this manual to familiarize yourself with specific requirements, including maximum external static pressure, air temperature rise, CFM, and motor speed connections. Keep this literature for future reference.

WARNING

Failure to follow these instructions exactly may result in fire or explosion, causing property damage, personal injury, or loss of life.

• Do not store or use gasoline or other flammable vapors and liquids near this or any other appliance.
• What to do if you smell gas:
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your building.
• Immediately call your gas supplier from a neighbor's phone and follow their instructions. If you cannot reach your gas supplier, call the fire department.
• Installation and service must be performed by a qualified installer, service agency, or the gas supplier.

WARNING

To prevent property damage, personal injury, or death, do not store combustible materials or use gasoline or other flammable liquids or vapors near this appliance.

WARNING

Should overheating occur or the gas supply fail to shut off, turn off the manual gas shutoff valve external to the furnace before turning off the electrical supply.

CAUTION

Sheet metal parts, screws, clips, and similar items have sharp edges. Installers and service personnel must exercise caution.

These instructions cover the outdoor installation of single package heating and cooling units. Refer to the Specification Sheet for accessory information.

*NOTE: Contact your distributor or our website for the applicable Specification Sheet.

WARNING

Do not connect to or use any device not certified by the manufacturer for this unit. Doing so may result in property damage, personal injury, reduced performance, or hazardous conditions.

WARNING

To avoid property damage, personal injury, or death, do not use this unit if any part has been under water. Immediately call a qualified service technician to inspect the furnace and replace any part of the control system or gas control that has been under water.

WARNING

This unit must not be used as a "construction heater" during the finishing phases of new construction. This use can lead to premature unit failure due to extremely low return air temperatures and exposure to corrosive or dirty atmospheres.

WARNING

HIGH VOLTAGE! Disconnect all power before servicing or installing. Multiple power sources may be present. Failure to do so may cause property damage, personal injury, or death.

CARBON MONOXIDE POISONING HAZARD

Special Warning for Installation of Furnace or Air Handling Units in Enclosed Areas such as Garages, Utility Rooms or Parking Areas

Carbon monoxide (CO) producing devices (e.g., automobiles, space heaters, gas water heaters) should not be operated in enclosed areas like unventilated garages, utility rooms, or parking areas due to the danger of CO poisoning from exhaust emissions. If a furnace or air handler is installed in such an area, adequate, direct outside ventilation is required.

This ventilation is necessary to prevent CO poisoning, which can occur if a CO-producing device continues to operate in the enclosed area. CO emissions can be recirculated throughout the structure if the furnace or air handler is operating. CO can cause serious illness, including permanent brain damage or death.

RIESGO DE INTOXICACIÓN POR MONÓXIDO DE CARBONO

Advertencia especial para la instalación de calentadores o manejadoras de aire en áreas cerradas como estacionamientos o cuartos de servicio. Los equipos o aparatos que producen monóxido de carbono (tal como automóvil, calentador de gas, calentador de agua por medio de gas, etc.) no deben ser operados en áreas cerradas debido al riesgo de envenenamiento por monóxido de carbono (CO) que resulta de las emisiones de gases de combustión. Si el equipo o aparato se opera en dichas áreas, debe existir una adecuada ventilación directa al exterior. Esta ventilación es necesaria para evitar el peligro de envenenamiento por CO, que puede ocurrir si un dispositivo que produce monóxido de carbono sigue operando en el lugar cerrado. Las emisiones de monóxido de carbono pueden circular a través del aparato cuando se opera en cualquier modo. El monóxido de carbono puede causar enfermedades severas como daño cerebral permanente o muerte.

RISQUE D'EMPOISONNEMENT AU MONOXYDE DE CARBONE

Avertissement spécial au sujet de l'installation d'appareils de chauffage ou de traitement d'air dans des endroits clos, tels que les garages, les locaux d'entretien et les stationnements. Évitez de mettre en marche les appareils produisant du monoxyde de carbone (tels que les automobiles, les appareils de chauffage autonome, etc.) dans des endroits non ventilés tels que les garages, les locaux d'entretien et les stationnements. Si vous devez faire fonctionner ces appareils dans un endroit clos, assurez-vous qu'il y ait une ventilation directe provenant de l'extérieur. Cette ventilation est nécessaire pour éviter le danger d'intoxication au CO pouvant survenir si un appareil produisant du monoxyde de carbone continue de fonctionner au sein de la zone confinée. Les émissions de monoxyde de carbone peuvent être recirculées dans les endroits clos, si l'appareil de chauffage ou de traitement d'air sont en marche. Le monoxyde de carbone peut causer des maladies graves telles que des dommages permanents au cerveau et même la mort.

GENERAL INFORMATION

WARNING

To prevent property damage, personal injury, or death due to fire, explosions, smoke, soot, condensation, electric shock, or carbon monoxide, this unit must be properly installed, repaired, operated, and maintained.

This unit is approved for outdoor installation ONLY. Rated performance is achieved after 20 hours of operation at the specified airflow. See product specification sheets for light commercial models, available at www.daikinac.com. Navigate to the commercial products menu, then the product type submenu.

For safe and efficient operation, the unit must be installed, operated, and maintained according to these instructions, local building codes, and the latest edition of the National Fuel Gas Code NFPA54/ANSI Z223.1 and National Standard of Canada CAN/CSA B149 Installation Codes.

EPA Regulations

The U.S. Environmental Protection Agency (EPA) has regulations regarding refrigerant introduction and disposal. Failure to comply may harm the environment and result in fines. Consult the local EPA office for questions.

National Codes

This product is designed for installation per National Codes. The installer is responsible for compliance with National and local codes and regulations.

Heating and cooling capacities should meet or exceed the design loads of the area. Load calculations should follow approved methods, ASHRAE Guide, or Manual J.

Obtain standards from: American National Standards Institute, 25 West 43rd Street, 4th Floor, New York, NY 10036.

System design and installation should also follow accepted industry guides like ASHRAE Handbooks. The manufacturer is not responsible for equipment installed in violation of any code or regulation.

Mechanical installation involves connecting the unit to building services, including supply and return duct connections and drain connections. Internal systems are factory-installed and tested.

Units are typically installed on a steel roof mounting curb assembly. The model number on the unit's identification plate specifies components like refrigeration tonnage, heating output, and voltage.

Inspect the unit for damage, including cabinetry. Tighten any loose bolts or screws. If damage is found:

1. Note any visible damage on the delivery receipt.
2. Notify the carrier promptly and request an inspection.
3. For concealed damage, notify the carrier as soon as possible, preferably within 5 days.
4. File a claim with supporting documents: Original Bill of Lading, paid freight bill, original invoice, and carrier inspection report. The carrier is responsible for inspection and claim investigation. The distributor or manufacturer will not accept claims from dealers for transportation damage.

NOTE: When inspecting for transportation damage, remove all packaging materials. Recycle or dispose of packaging according to local codes.

Pre-Installation Checks

Read all instructions carefully before installation. Ensure all steps are understood and any special considerations are addressed. Gather all necessary tools, hardware, and supplies.

WARNING

To prevent equipment damage, property damage, personal injury, or death, observe these points during installation:

IMPORTANT NOTE: Remove wood shipping rails before installing the unit.

All Installations:

IMPORTANT NOTE: Energize the unit for 24 hours before compressor start-up to warm the crankcase heater. Failure to do so may cause compressor damage.

NOTE: Appliance is shipped for vertical duct application.

Proper installation ensures trouble-free operation. Improper installation can lead to noise, property damage, dangerous conditions, injury, or personal property damage, none of which are covered by warranty. Provide this booklet to the user and explain its provisions. The user should keep these instructions for future reference.

• Mount the unit level for proper flame pattern and condensate drainage.
• The flue outlet must be at least 12 inches from any building opening and 3 feet above any forced air inlet within 10 feet. Economizer/fresh air intakes are not affected.
• To prevent heat exchanger corrosion, do not locate the unit where outdoor air (combustion air) is frequently contaminated by chlorine or fluorine compounds (e.g., from swimming pool chemicals, bleaches, paint strippers, adhesives, paints, sealers, waxes, solvents). Industrial processes can also be sources.
• Do not connect the unit to a chimney flue serving a solid fuel appliance.
• To prevent illness or death, do NOT locate outside air intake devices (economizer, fresh air intakes) too close to exhaust outlets, gas vent terminations, or plumbing vents. Consult local codes for specific distances.
• Maintain minimum clearances for fire protection, operation, and service access. These must be permanently maintained.
• The combustion air inlet and flue outlet must never be obstructed. Prevent economizer/fresh air dampers from being blocked by snow or debris. Elevate the unit if necessary in certain climates.
• When heating, the return air temperature entering the unit must be a minimum of 55°F.

Ground Level Installations Only:

• For ground installations adjacent to the building, a level concrete base is recommended. The base should be 3 inches larger than the unit footprint and a minimum of 3 inches thick.
• Position the base to prevent water runoff from higher ground from collecting in the unit.

Roof Top Installations Only:

• Ensure the roof has sufficient structural strength for the unit's weight and potential snow or water loads per local codes. Consult a structural engineer.
• The unit may be installed directly on wood floors or Class A, B, or C roof covering material.
• Provide a safe, flat surface for service personnel.
• Maintain a minimum 36" clearance to any combustible material on the furnace access side, as indicated on the unit data plate. Keep combustible materials out of this area.
• This 36" clearance is also required for proper combustion air and flue gas flow. The combustion air intake and flue discharge must not be blocked by snow or debris.
• Maintain adequate clearances from the furnace flue discharge to adjacent public walkways, buildings, building openings, or openable windows per the National Fuel Gas Code ANSI Z223.1/NFPA 54.
• Maintain a minimum horizontal clearance of 48" from the furnace flue discharge to electric meters, gas meters, regulators, and relief equipment.

Unit Precautions

• Do not stand or walk on the unit.
• Do not drill holes in panels or the base frame except where indicated. Unit access panels provide structural support.
• Do not remove access panels until the unit is installed on the curb or structure.
• Do not roll the unit across a finished roof without prior owner or architect approval.

• Do not skid or slide the unit, as this may damage the base. Store on a flat, level surface. Protect the condenser coil from damage.

Roof Curb Installations Only:

Curb installations must comply with local codes and National Roofing Contractors Association guidelines. Ensure the roof curb is firmly and permanently attached to the roof structure. Check fastening methods before setting the unit on the curb.

Full perimeter roof curbs are available from the factory, shipped unassembled. Field assembly, squaring, leveling, and mounting are the installer's responsibility. Required hardware is included with the curb accessory.

WARNING

To prevent equipment damage, property damage, personal injury, or death, observe these points during installation:

• Determine sufficient structural support before locating and mounting the curb and unit.
• Construct ductwork per industry guidelines. Place ductwork into the roof curb before mounting the unit. Curbs include duct connection frames. Cantilevered curbs are not factory available.
• Curb insulation, cant strips, flashing, and roofing material are furnished by the contractor.
• Support curbs on parallel sides by roof members.
• Ensure roof members do not penetrate supply and return duct opening areas to prevent unit damage.

Clearances

A diagram illustrates minimum clearances: 24" MIN. and 36" MIN. A 36" minimum clearance is required between multiple units' condenser coils.

Maintain adequate clearance around the unit for safety, service, maintenance, and operation. A 48" clearance is recommended on all sides for parts replacement, service access, ventilation, and condenser airflow. The top of the unit must remain unobstructed. If units are under an overhang, maintain a minimum 48" clearance and provide means to deflect warm discharge air. Install units away from building exhausts to prevent intake of exhaust air.

NOTE: If using the 36" minimum clearance on the control panel side of a DRG unit, a flue extension kit is required to prevent flue gas recirculation. See table below for kit selection.

NOTE: Unit and curb accessories allow vertical duct installation before unit placement. Duct installation after unit placement is not recommended.

CAUTION

Curbs may look similar. Check job plans and curb assembly markings carefully to avoid incorrect positioning. Instructions may vary by curb style.

Refer to the roof curb manual for assembly and installation instructions.

ROOF CURB POST-INSTALLATION CHECKS

After installation, check the curb top, duct connection frame, and duct flanges for proper gasket application. If gasket is loose, re-apply with strong weather-resistant adhesive.

Protrusion

Inspect the curb to ensure utility services (electric) routed through it do not protrude above the curb.

CAUTION

If protrusions exist, do not attempt to set the unit on the curb.

ROOF TOP DUCT CONNECTIONS

Install all duct connections on the unit before placing it on the rooftop.

Horizontal Discharge

Refer to IOD-7082 for installing horizontal duct covers. Flexible duct connectors are recommended between the unit and ducts. Insulate and weatherproof all external ductwork and joints as required by local codes.

RIGGING DETAILS

WARNING: Keep the unit upright during all rigging and moving operations. Use an adequate cable sling for lifting with a crane.

CAUTION

If lifting two units at a time, do not use the fork holes on the condenser end. Minimum fork length is 42" (48" recommended) to prevent unit damage.

Forks provisions are included in the unit base frame only. No other fork locations are approved.

WARNING

To prevent equipment damage, property damage, personal injury, or death, observe these points when installing the unit:

• Lift the unit by the four lifting holes at the base frame corners.
• Attach lifting cables with shackles.
• Ensure the distance between the crane hook and the unit top is not less than 60".
• Use two spreader bars spanning over the unit to prevent cabinet damage from lift cables. Spreader bars must be long enough so cables do not contact the unit.
• Remove wood struts from beneath the unit base frame before setting it on the roof curb. These struts protect the base from forklift damage. They are removed by extracting sheet metal retainers and pulling the struts through the base. Refer to the rigging label on the unit.

Important: For bottom discharge with a roof curb, attach ductwork to the curb before installing the unit. Ductwork dimensions are in the Roof Curb Installation Instructions.

Refer to Roof Curb Installation Instructions for proper curb installation, complying with the National Roofing Contractors Association Manual.

Horizontal Discharge Duct Connections

Diagram shows dimensions for supply (12" x 17") and return (11" x 25") duct connections.

Rigging Removal

CAUTION

To prevent unit damage, do not allow crane hooks and spreader bars to rest on the unit's roof.

Remove spreader bars, lifting cables, and other rigging equipment.

ELECTRICAL WIRING

Weights and Center of Gravity are provided to assist in determining rigging requirements.

The numbers may slightly vary depending on installed options.

NOTE: Unit should be lifted at a point above the center of gravity.

CAUTION

To prevent severe damage to the unit's bottom, do not use a forklift after wood struts have been removed.

Bring the condenser end of the unit into alignment with the curb first. Carefully lower the unit onto the roof mounting curb. Center the unit on a rectangular cantilever curb. Check alignment and orientation of supply and return openings with ductwork.

WARNING

HIGH VOLTAGE! Disconnect all power before servicing or installing. Multiple power sources may be present. Failure to do so may cause property damage, personal injury, or death.

WARNING

HIGH VOLTAGE! To avoid personal injury or death from electrical shock, do not tamper with factory wiring. Internal wiring is factory-installed and tested. Contact your local representative for assistance.

CAUTION

Protect wiring from sharp edges. Follow national and local electrical codes and ordinances. Do not route wires through removable access panels.

CAUTION

Conduit and fittings must be weather-tight to prevent water entry into the building.

For unit protection, use a fuse or HACR circuit breaker rated appropriately. Do not exceed the maximum overcurrent device size shown on the unit data plate.

Make all line voltage connections through weatherproof fittings. Exterior power supply and ground wiring must be in approved weatherproof conduit.

Main power and low voltage wiring must comply with these instructions, the National Electrical Code (ANSI/NFPA 70), and all local codes and ordinances.

The unit is factory wired for the voltage shown on the unit's data plate.

NOTE: If supply voltage is 208V, move the transformer primary lead from the 230V tap to the 208V tap. Refer to the unit wiring diagram.

Main power wiring should be sized for minimum circuit ampacity per the unit data plate and NEC Article 310. Increase wire size if necessary to prevent excessive voltage drop (maximum 3% drop).

CAUTION

To avoid risk of property damage, personal injury, or fire, use only copper conductors.

Diagram: Power and Low Voltage Block Connections.

CAUTION

To prevent improper and dangerous operation due to wiring errors, label all wires before disconnecting during servicing. Verify proper operation after servicing.

NOTE: A weather-tight disconnect switch, sized for the unit's total load, must be field or factory installed. An external disconnect may be mounted on the exterior panel.

Ensure the data plate is not covered by the disconnect switch.

• Some disconnect switches are not fused. Protect power leads at the point of distribution per the unit data plate.
• Ground the unit per local codes or the latest National Electrical Code (ANSI/NFPA 70) and Canadian Electrical Code, CSA C22.1, Part 1. Use the provided ground lug; do not use it for a neutral conductor.
• Connect power wiring to the electrical power block in the main control box.

NOTE: Depending on installed options, component locations may vary.

WARNING

Operating the unit with improper line voltage or excessive phase unbalance can cause damage or failure, which is not covered by warranty.

Areas Without Convenience Outlet

It is recommended to provide an independent 115V power source near the rooftop unit for portable lights and tools used by service mechanics.

NOTE: Refer to local codes for requirements. These outlets can also be factory installed.

Units Installed on Roof Tops

Main power and low voltage wiring can enter through the condenser end or the roof curb. Install weatherproof conduit connectors at desired locations. Seal all holes in the unit base (including around conduit nuts) to prevent water leakage into the building. All required conduit and fittings are field supplied.

Supply voltage to the rooftop unit must not vary by more than 10% of the data plate value. Phase voltage unbalance must not exceed 2%. Contact the local power company for correction.

GAS SUPPLY PIPING

WARNING

To prevent personal injury or death due to improper installation, adjustment, alteration, service, or maintenance, refer to this manual. Consult a qualified installer, servicer agency, or gas supplier for assistance.

IMPORTANT NOTE: This unit is factory set to operate on natural gas at the altitudes shown on the rating plate.

Diagram: Electrical Entrance and Thru Curb (Bottom View of Unit).

Low Voltage Control Wiring

1. A 24V thermostat is required for unit operation.
2. Locate the thermostat or remote sensor in the conditioned space to sense average temperature. Avoid locations exposed to supply air, sunlight, or heat sources. Follow device installation instructions.
3. Use #18 AWG wire for 24V control wiring up to 75 feet; #16 AWG for runs up to 125 feet; #14 AWG for runs up to 200 feet. Low voltage wiring may be NEC Class 2 where permitted by local codes.
4. Route low voltage control wires from sub-base terminals to the unit. Wiring should enter through the condenser panel opening or curb. Connect thermostat and accessory wiring to low voltage terminal block TB1 in the main control box.

NOTE: Field-supplied conduit may be needed depending on unit/curb configuration. Use #18 AWG solid conductor wire for thermostat connections. Do not use wire larger than #18 AWG. A transition to #18 AWG wire may be required before entering the thermostat sub-base.

NOTE: Refer to unit wiring diagrams for thermostat or remote sensor connections.

INLET GAS PRESSURE

Minimum supply pressure should not vary from the table value to ensure dependable ignition. Gas input must not exceed the rated input on the rating plate. Overfiring can result in premature heat exchanger failure.

Piping

IMPORTANT NOTE: To avoid unsatisfactory operation or equipment damage due to under-firing, do not undersize natural/propane gas piping from the meter/tank to the unit. When sizing a trunk line, include all appliances on that line that could operate simultaneously.

Gas line installation must comply with local codes or the latest edition of the National Fuel Gas Code NFPA 54 / ANSI Z223.1.

Natural Gas Connection

Pressure= .50 PSIG or less and Pressure Drop of 0.3" W.C. (Based on 0.60 Specific Gravity Gas)

CFH = BTUH Furnace Input / Heating Value of Gas (BTU/Cubic Foot)

Follow Proper Piping Practice drawing for general layout. Rules include:

1. Use black iron pipe and fittings for supply piping. Flex connectors and copper piping are permitted if compliant with local codes.
2. Use pipe joint compound on male threads only; it must be resistant to the fuel used.
3. Use ground joint unions.
4. Install a drip leg (min. 3 inches long) to trap dirt and moisture before it enters the gas valve.
5. Use two pipe wrenches when connecting to the gas valve to prevent turning.
6. Install a manual shut-off valve within six feet of the unit, between the meter and the unit.
7. Tighten all joints securely.
8. Connect to building piping using one of these methods:
   • Rigid metallic pipe and fittings.
   • Semirigid metallic tubing and metallic fittings (Aluminum alloy tubing must not be used outdoors).
   • Listed gas appliance connectors used per their listing, in the same room as the equipment. Always use a new connector.
9. Protect connectors or tubing from physical and thermal damage. Coat aluminum alloy tubing and connectors to prevent external corrosion when in contact with masonry, plaster, insulation, or subject to repeated wetting (not rain water, detergents, or sewage).

NOTE: Unit gas supply entrance is factory sealed with plugs. Keep plugs in place until gas supply is ready. Replace plugs with supplied grommets and install gas supply line.

Gas Piping Checks

CAUTION

To prevent property damage or personal injury due to fire, perform these gas connection and pressure testing instructions:

• Leak test the unit and its gas connections before operation. Never use a match or open flame for leak testing. Do not exceed specified test pressures, as higher pressures may damage the gas valve and cause overfiring, leading to premature heat exchanger failure.
• Disconnect the unit and shut-off valve from the gas supply during pressure testing of that system at pressures exceeding 1/2 PSIG (3.48 kPa).
• Isolate the unit from the gas supply system by closing its manual shut-off valve during pressure testing at pressures equal to or less than 1/2 PSIG (3.48 kPa).

WARNING

To avoid property damage or personal injury, ensure there is no open flame in the vicinity during air bleeding.

Air in the gas supply line after leak testing must be bled by loosening the ground joint union until pure gas is expelled. Tighten the union and wait five minutes for gas to dissipate. Ensure no open flame is present during bleeding.

The unit is placed in operation by closing the main electrical disconnect switch.

Roof Top Location and Installation

Gas supply piping location and installation for rooftop units must comply with local codes or the National Fuel Gas Code ANSI Z223.1/NFPA 54.

A manual gas shut-off valve must be field installed external to the unit. A drip leg must be installed near the inlet connection. A ground joint union connection is required between the shut-off valve and the unit connection to the gas valve to permit burner assembly removal for servicing.

1. Route gas piping to avoid interfering with access panel removal. Support and align piping to prevent strain or misalignment of the manifold assembly.
2. All units have standard female 1/2" NPT pipe connections. Gas supply piping size depends on run length, number of units, gas characteristics, BTU requirement, and available supply pressure. Comply with local codes and NFPA 54 / ANSI Z223.1.

NOTE: Unit connection size does not determine supply line size.

With all units on a common line operating at full fire, natural gas supply pressure should be adjusted to approximately 7.0" w.c. at the unit gas valve. If pressure exceeds 10.0" w.c., install an external positive shut-off service pressure regulator. The unit will not function satisfactorily if supply pressure is less than 5.0" w.c. or greater than 10.0" w.c.

NOTE: A minimum horizontal distance of 48" is required between the regulator and the furnace flue discharge.

Seal all pipe connections with a pipe thread compound resistant to the fuel used. Use a soapy water solution to check joints for leaks. Test gauge connection taps are provided on the gas valve for measuring supply (main) and manifold gas pressure.

WARNING

This unit and its shutoff valve must be DISCONNECTED from the gas supply system during any pressure testing of that system at test pressures exceeding 1/2 PSIG (13.8" w.c.).

CAUTION

This unit must be ISOLATED from the gas supply piping system by closing its manual shutoff valve during any pressure testing at pressures equal to or less than 1/2 PSIG.

Ensure no obstructions prevent combustion and ventilating air flow. A vent stack is not required and must never be used. The power venter supplies combustion air if passageways are clear and recommended external clearances are maintained.

CIRCULATING AIR AND FILTERS

Ductwork

Supply ductwork through a wall may be installed without clearance, but minimum unit clearances must be maintained. Provide an access panel large enough to inspect the air chamber downstream of the heat exchanger. Secure the cover tightly to prevent air leaks.

CONDENSATE DRAIN CONNECTION

A 3/4" female NPT drain connection is supplied on the unit end and bottom of the drain pan for condensate piping. An external trap must be installed for proper condensate drainage. Hand-tighten the drain fitting.

NOTE: Trap should be deep enough to offset maximum unit static difference. A minimum 4" trap is recommended.

Drain Connection

Install condensate drain trap as shown. Use 3/4" drain line and fittings or larger. Do not operate without the trap.

Horizontal Drain

Condensate drainage directly onto the roof may be acceptable per local code. A small drip pad (stone, mortar, wood, or metal) is recommended to prevent roof damage.

Vertical Drain

To use the bottom drain connection, move the drain plug from the bottom connection to the horizontal connection.

Cleaning

Drain pans may accumulate moisture, leading to algae and fungus growth from airborne bacteria and spores. Periodic cleaning prevents drain blockage.

STARTUP, ADJUSTMENTS, AND CHECKS

WARNING

HIGH VOLTAGE! To avoid personal injury or death from electrical shock, bond the unit frame to the building electrical ground using the provided terminal or other acceptable means. Disconnect all power before servicing or installing.

Pre-Startup Instructions - General

CAUTION

To prevent property damage or personal injury, do not start the unit until all necessary pre-checks and tests are performed.

Before starting Startup, Adjustments, and Checks, complete the following steps in the building.

WARNING

MOVING MACHINERY HAZARD! To prevent personal injury or death, disconnect power to the unit and padlock the "OFF" position before servicing fans.

CAUTION

To prevent property damage or personal injury, do not start the unit until all necessary pre-checks and tests are performed.

This unit has an electronic ignition device for automatic main burner lighting and a power vent blower for exhausting combustion products.

For new installations or after major component replacement, check unit operation. If sparking, odors, or unusual sounds occur, shut off electrical power and recheck wiring or blower motor obstructions. Remove duct covers before operating.

The Startup, Adjustments, and Checks procedure provides a step-by-step sequence for proper startup. Air balancing is not part of this procedure but is important for system startup. The procedure at ambient temperatures below 55°F should be limited to a readiness check of the refrigeration system, with final checks and calibration performed when ambient rises above 55°F.

Temporary Heating Or Cooling

If the unit is used for temporary heating or cooling, a "Startup, Adjustments, and Checks" must be performed per this manual. Damage or repairs due to non-compliance are not covered by warranty. After temporary use, inspect coils, fans, and motors for construction dust and dirt, and install new filters.

Contractor Responsibility

The installing contractor must ensure:

• Supply and return air ductwork is in place, properly sealed, and matches installation instructions.
• Thermostats are mounted and wired per installation instructions.
• All electric, gas, hot water, or steam line connections, and condensate drain installation are made and functional for all units simultaneously.
• Venting and combustion air requirements are met.
• Air filters are in place.
• Input rate and temperature rise are adjusted per the rating plate.

Roof Curb Installation Check

Inspect the roof curb for correct installation. The unit and curb assembly should be level. Check roof curb flashing, especially at corners, for good workmanship. Check for gasket leaks. Report any deficiencies separately to the contractor.

Obstructions, Fan Clearance and Wiring

Remove any construction and shipping materials. Manually rotate all fans to check clearances and free rotation. Check for loose bolts and screws; re-tighten if necessary. Re-tighten all electrical connections.

Field Duct Connections

Verify all duct connections are tight and there is no air bypass between supply and return.

Filter Section Check

Remove filter access panels and check filter installation. Note airflow arrows on filter frames.

Pre-startup Precautions

Ensure the unit is properly grounded. Check ground lug connection tightness before closing the circuit breaker or disconnect switch. Verify supply voltage on the line side of the disconnect matches the unit identification plate and is within the utilization voltage range (see Appendix B Electrical Data).

System Voltage: Nominal voltage assigned to a circuit or system for voltage class designation.

Nameplate Voltage: Voltage assigned to equipment for voltage class and defining minimum/maximum operating voltage.

Utilization Voltage: Line terminal voltage at which equipment must perform satisfactorily. Check for phase unbalance if supply voltage is stable within the utilization range.

Calculate Percent Voltage Unbalance (Three Phase Models Only):

Percent Voltage Unbalance = 100 x (Maximum Voltage Deviations from Average Voltage) / Average Voltage. Percent voltage unbalance must not exceed 2%.

AIR FLOW ADJUSTMENTS

After final adjustments, check motor current draw against the full load rating. Amperage must not exceed the motor nameplate service factor. Total airflow must meet furnace requirements.

If an economizer is installed, check unit operating balance at full and minimum outside air.

NOTE: Never run high stage CFM below 300 CFM per ton to avoid evaporator freezing or poor unit performance.

Standard Static Drive Motor

Adjust CFM by changing low voltage leads on terminal block TB1. Refer to Appendix A for blower performance data at each speed tap and Appendix D for maximum/minimum airflow.

NOTE: If more than one lead is energized simultaneously, the motor runs at the higher numerical speed tap.

Purple wire Y2 (High Cool) connects to TB1-T3. These wires can be moved together or separately to unoccupied terminals T4 or T5.

NOTE: For proper operation, Y2 should have a higher speed setting than G, Y1, and W1.

For gas heat units, adjust airflow so air temperature rise falls within the ranges stated on the Data Plate.

Electrical Input Check

Perform a preliminary check of evaporator fan ampere draw and verify it does not exceed motor nameplate amps. A final check should be made after air balancing (see Appendix B).

GAS SYSTEM CHECK

Pre-Operation Checks:

1. Close the manual gas valve external to the unit.
2. Turn off electrical power supply to the unit.
3. Set heating setpoint to its lowest possible setting.
4. Remove the heat exchanger door by removing screws.
5. This unit uses an ignition device that automatically lights the main burner. DO NOT attempt to light the burner by any other method.
6. Move the gas control valve switch to the OFF position.
7. Wait five minutes to clear any gas.
8. Smell for gas, including near the ground. If gas is detected after five minutes, follow the "WHAT TO DO IF YOU SMELL GAS" warning on page 2. If no gas smell is noted, move the gas control valve switch to the ON position.
9. Replace the heat exchanger door.
10. Open the manual gas valve external to the unit.
11. Turn on the electrical power supply.
12. Set heating setpoint to the desired setting.

Gas Supply Pressures & Regulator Adjustments

WARNING

Should overheating occur or the gas supply fail to shut off, turn off the manual gas shutoff valve external to the unit before turning off the electrical supply.

WARNING

To avoid property damage, personal injury, or death, do not fire the gas unit with the flue box cover removed. The furnace access panel must always be secured during operation, except when gas pressures are being measured by qualified service personnel.

Gas Supply And Manifold Check

Gas supply pressure and manifold pressure with burners operating must match the rating plate specifications.

Gas Inlet Pressure Check

Check and adjust gas inlet pressure according to the fuel type.

With Power And Gas Off:

1. Connect a manometer to the gas valve inlet pressure tap.

Inlet gas pressure can also be measured by removing the dripleg cap and installing a predrilled cap with a hose fitting.

With Power And Gas On:

1. Put the unit into heating cycle and turn on all other gas consuming appliances.

INLET GAS PRESSURE

If operating pressures differ, make necessary regulator adjustments, check piping size, or consult the local utility.

Manifold Pressure Check and Adjustment

The gas valve has a pressure tap for manifold pressure measurement. Measure manifold pressure with burners operating.

1. With the disconnect switch open, remove the field-connected thermostat wire from terminal R and W1 on TB1. Place a jumper wire between R and W1 to engage heating.
2. Refer to the gas input check section figure for gas valve adjustment.

To adjust the pressure regulator, remove the adjustment screw cover. Turn the screw clockwise to increase pressure, counterclockwise to decrease. Make only small variations with the regulator; use burner orifices for major changes. The measured input rate must not exceed the rating specified on the unit rating plate.

High stage manifold pressure should be between 2.7 and 3.3 inches water column (3.0 nominal).

Gas Input Check

The contractor is responsible for adjusting the gas input to the unit.

The unit is subject to considerable jarring during shipment; test all gas connections and joints for tightness. Check gas piping downstream from the unit inlet for leaks during the subsequent sequence check.

Supply gas pressure should be adjusted to 7.0" w.c. with burners operating. For multiple units on a common line, check pressures with all units at full fire. A supply pressure tap is on the upstream side of the gas valve; a manifold pressure tap is on the manifold side. Normal manifold pressure is 3.0" w.c. Minimum supply pressure is 5.0" w.c.

Do not adjust the built-in pressure regulator unless the supply pressure is at least 5.0" w.c.

Diagram: Flame Sensor and Ignition Electrode Location.

NOTE: Gas appliances above 2000 ft. elevation require 4% derating per 1000 ft. Variance in gas heating value and specific gravity requires manifold pressure changes. Input must be adjusted at the installation site. Follow ANSI Z223.1 "Procedures To Be Followed To Place An Appliance in Operation". Refer to the "User's Information Manual" for additional gas furnace information.

To measure gas input, use a gas meter and proceed as follows:

1. Turn off gas supply to all other appliances except the unit.
2. With the unit operating, time the smallest dial on the meter for one complete revolution. If it's a 2 cubic foot dial, divide seconds by 2; if it's a 1 cubic foot dial, use seconds as is. This gives seconds per cubic foot of gas delivered.
3. INPUT = (GAS HTG VALUE x 3600) / SEC. PER CUBIC FOOT.

Example: Natural gas (1000 BTU/cu ft) with 34 seconds/cu ft: Input = 1000 x 3600 / 34 = 106,000 BTU/hr.

NOTE: Obtain BTU content from the gas supplier. Measured input must not exceed the unit rating plate value.

Adjust input rate by varying the gas pressure regulator adjustment. Make adjustments with the furnace operating at high fire and normal temperature. Use a manometer to verify pressure is within the specified range (see figures for manometer connections). Clockwise rotation of the regulator screw increases pressure/flow; counterclockwise decreases it. Furnace temperature rise must be within the range specified on the unit data plate.

NOTE: Thermal efficiency is a rating determined under continuous operating conditions, independent of the installed system.

Diagram: White-Rodgers Gas Control Valve Connected to Manometer Pressure Adjustments.

To connect manometer to gas valve:

1. Back outlet pressure tap screw (inside inlet pressure boss) out one turn (counterclockwise, not more than one turn).
2. Attach a hose and manometer to the outlet pressure boss.

To remove manometer from gas valve:

1. Remove manometer hose from outlet pressure boss.
2. Turn outlet pressure tap screw in to seal pressure port (clockwise, 7 in-lb. minimum).
3. Turn on electrical power and gas supply.
4. Turn on system power and energize valve.
5. Use leak detection solution or soap suds to check pressure boss screw for leaks. Bubbles indicate a leak. SHUT OFF GAS AND FIX ALL LEAKS IMMEDIATELY.

CAUTION

To prevent unreliable operation or equipment damage, gas manifold pressure must be as specified on the unit rating plate. Make only minor adjustments using the gas valve pressure regulator.

Relight all other appliances turned off in step 1 of gas input check. Ensure all pilot burners are operating.

Temperature Rise Check

Check temperature rise through the unit by placing thermometers in supply and return air registers near the unit. Thermometers must not sample temperature directly from heat exchangers to avoid false readings.

1. All registers must be open; all duct dampers must be in their final (fully or partially open) position. Operate the unit for 15 minutes before taking readings.
2. The temperature rise must be within the range specified on the rating plate.

NOTE: Air temperature rise is the difference between supply and return air temperature.

With a properly designed system, temperature rise will normally be obtained at rated input with recommended blower speed.

If correct temperature rise is not obtained, change blower speed. Higher speed lowers rise; slower speed increases rise.

NOTE: Blower speed MUST be set to provide the correct air temperature rise through the unit as marked on the rating plate.

Normal Sequence of Operation

Heating

This unit has one (RS) Manual Reset Limit Control Switch. Check that the limit has not tripped. It may arrive tripped due to shipping shock.

DRG Model Wiring (Standard Static)

Diagrams show wiring for GR (FAN), YL (Cooling Stage 1), WH (Heating Stage 1), PU (Cooling Stage 2).

• Move YELLOW (YL) wire from TB1-T1 to T2 or T3 to change blower speed during cooling stage 1 operation. (Do not move YL and PU to the same taps).
• Move WHITE (WH) wire from TB1-T2 to T3 to change blower speed during heating stage 1 operation.
• Move PURPLE (PU) wire from TB1-T3 to T4 or T5 to change blower speed during cooling stage 2 operation. (Do not move YL and PU to the same taps).

DRG Model Wiring (High Static)

• Move YELLOW (YL) wire from TB1-T1 to T2 or T3 to change blower speed during cooling stage 1 operation. (Do not move YL and PU to the same taps).
• Move WHITE (WH) wire from TB1-T6 to T7 to change blower speed during heating stage 1 operation.
• Move PURPLE (PU) wire from TB1-T3 to T4 or T5 to change blower speed during cooling stage 2 operation. (Do not move YL and PU to the same taps).

DRG OPERATION AND WIRE RANGE CHART (STANDARD STATIC)

DRG OPERATION AND WIRE RANGE CHART (HIGH STATIC)

X = 24V SIGNAL

→ RANGE OF AVAILABLE TAPS

FOR WIRE COLOR INFORMATION AND PLACEMENT VIEW DRG MODEL WIRING SECTION.

If the vent motor runs but the unit does not attempt ignition, check if the ALS (Auxiliary High Limit Control Switch) requires resetting.

This unit has an ignition control that automatically lights the main burner. DO NOT attempt to light the main burners by any other method.

Sequence of Operation (Heating):

1. R and W thermostat contacts close, initiating a call for heat.
2. Integrated control module performs safety circuit checks.
3. Inducer draft blower energizes for 30 seconds (pre-purge), closing pressure sensor contacts.
4. At end of pre-purge, control module sets induced draft blower to light-off setting.
5. Once light-off pressure setting is verified, spark igniter and gas valve energize for 4 seconds.

NOTE: The igniter produces a very intense electrical spark that ignites the gas.

6. Integrated control module monitors flame presence. Gas valve remains open only if flame is detected.
7. The 30-second HEAT FAN ON delay begins after the main burner lights.
8. The unit delivers heat until the thermostat is satisfied; the control module continuously monitors safety circuits.
9. R and W thermostat contacts open, completing the call for heat; gas valve de-energizes.
10. Induced draft blower continues for a 30-second post-purge.
11. Ignition control times the HEAT FAN OFF delay (adjustable 90/120/150/180 seconds, factory set at 150).

NOTE: This delay allows additional heat in the heat exchanger to transfer to the conditioned space. After the delay, the blower de-energizes.

Unit Shutdown

1. Set room heating setpoint to the lowest setting.
2. Turn off electrical power supply to the unit.
3. Remove the heat exchanger door by removing screws.
4. Move the gas control valve switch to the OFF position.
5. Close the manual gas shut-off valve external to the unit.
6. Replace the heat exchanger door.
7. If cooling and/or air circulation is desired, turn ON the gas control valve switch and electrical power.

Automatic Reset High Limit Control (LS)

Located in the burner compartment, its sensing element projects through the blower section bulkhead, sensing temperature at the rear of the furnace. It cycles the furnace off if temperature exceeds 100°F plus maximum rise.

Auxiliary High Limit Control (ALS)

Located in the blower compartment, it senses air temperature within the blower compartment and protects filters from excessive temperature. It shuts down the furnace if excessive temperatures are sensed. Elevated temperatures are usually caused by blower failure. Determine and repair the cause before resetting.

Blocked Inlet Limit Control

Located in the burner compartment at the top of the burner assembly, it senses high temperature if the burner inlet is blocked. Determine and repair the cause before resetting this manual reset control.

WARNING

To avoid property damage, personal injury, or death due to fire or explosion, a qualified servicer must investigate the reason for the rollout protection device opening before manually resetting it.

Refrigeration System Checks

This unit uses thermal expansion valves. Ensure compressor hold-down bolts and vibration grommets are secure. Check all piping for damage and leaks. The system is factory charged; field charging is unnecessary. Factory refrigerant charge is on the unit's nameplate.

To confirm charge levels or add charge due to a leak, evacuate the system and recharge to the unit's nameplate specifications. The unit is rated for cooling at AHRI conditions: 80°F db/67°F wb indoor, 95°F db outdoor. Superheat should range from 9°F to 11°F, measured at the suction service port.

Start-Up Procedure and Checklist

Begin with power turned off at all disconnects.

1. Set thermostat system switch to "Cool," fan switch to "Auto," and temperature setting as high as possible.
2. Inspect all registers and set them to normal open position.
3. Turn on electrical supply at the disconnect.

Sequence of Operation (Cooling):

1. Turn fan switch to "ON" position. Blower operates after a 7-second delay.
2. Turn fan switch to "Auto" position. Blower stops after a 60-second delay.
3. Slowly lower cooling temperature until the unit starts. Compressor, blower, and fan should operate. Allow unit to run 10 minutes; verify cool air supply.
4. Turn temperature setting to the highest position to stop the unit. Indoor blower continues for 60 seconds.
5. Turn thermostat system switch to "OFF" and disconnect all power when servicing.

Refrigeration Sequence Check

1. 24VAC control voltage is provided by the control transformer to terminal XS, passing through safety shutdown devices before reaching terminals ES and R.
2. To simulate a mechanical call for cooling, lower the room cooling setpoint below the current room temperature. Cooling energizes when room temperature is above the setpoint.
3. UNIT WITH ECONOMIZER OPTION: Compressor circuit is interlocked through the economizer module. If outdoor air enthalpy is unsuitable for cooling, the economizer permits compressor energization.
4. Blower motor operates to provide cool supply air.
5. Compressor contactor closes, providing power to the compressor motor. Condenser fan motor is also energized through the compressor contactor.

WARNING

BURN HAZARD! DO NOT TOUCH! DISCHARGE LINE MAY BE HOT!

6. Check compressor operation. Scroll compressors MUST operate in proper rotation. Verify direction by checking compressor discharge line pressure or temperature after start-up. Discharge pressure and temperature should increase. If not, or if excessive noise occurs, perform checks.

If the compressor operates backward: disconnect power, lock OFF, switch two leads of the power supply at the Single Point Power Block, reconnect power, and check compressor/condenser fan motor operation.

7. With all safety devices closed, the system continues cooling until room temperature is satisfied.
8. Increasing the room cooling setpoint above the current temperature simulates a satisfied thermostat. Compressor and supply fan cycle off.
9. After approximately a 3-minute delay, compressor control circuits are ready for a subsequent cooling call.

Refrigeration Performance Check

Check compressor RLA against values in Appendix B. RLA draw may be lower at low load/ambient conditions and slightly exceed at high load/ambient conditions.

Final System Checks

1. Check that all supply and return air grilles are adjusted and the air distribution system is balanced for optimal heating/cooling compromise.
2. Check ductwork for air leaks (see Air Flow Adjustments sections).
3. Ensure the unit is free of "rattles." Check tubing for excessive vibration. Ensure tubes/lines are not rubbing against each other or sheet metal surfaces/edges; correct if necessary.
4. Set the thermostat for appropriate cooling, heating, or automatic changeover use.
5. Instruct the owner on unit operation, filter replacement, servicing, and correct thermostat operation.

MAINTENANCE

WARNING

ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD Failure to follow safety warnings exactly could result in dangerous operation, serious injury, death, or property damage. Improper servicing could result in dangerous operation, serious injury, death, or property damage.

• Before servicing, disconnect all electrical power to the furnace.
• When servicing controls, label all wires before disconnecting. Reconnect wires correctly.
• Verify proper operation after servicing.

WARNING

HIGH VOLTAGE! Disconnect all power before servicing or installing. Multiple power sources may be present. Failure to do so may cause property damage, personal injury, or death.

WARNING

To prevent personal injury or death due to improper installation, adjustment, alteration, service, or maintenance, refer to this manual. Consult a qualified installer, servicer agency, or gas supplier for assistance.

CAUTION

Sheet metal parts, screws, clips, and similar items have sharp edges. Installers and service personnel must exercise caution.

Preventive maintenance is the best way to avoid unnecessary expense and inconvenience. Have the system inspected by qualified service personnel at regular intervals, at least twice a year. Routine maintenance should cover:

1. Tighten all set screws and wire connections.
2. Clean evaporator and condenser coils mechanically or with cold water if necessary. Fouling on the entering air face can usually be removed by brushing.
3. Replace filters as needed (see below).
4. Check for condensate drain blockage.
5. Check power and control voltages.
6. Check running amperage.
7. Check operating temperatures and pressures.
8. Check and adjust temperature and pressure controls.
9. Check and adjust damper linkages.
10. Check operation of all safety controls.
11. Examine gas furnaces (see below and the User's Information Manual).
12. Check condenser fans and tighten set screws.

FILTERS

CAUTION

To prevent property damage, loss of equipment efficiency, or equipment damage due to dust and lint buildup on internal parts, NEVER operate the unit without an air filter installed in the return air system.

Filter replacement frequency varies by application. Replace filters at least every three (3) months during operating seasons.

Dirty filters are the most common cause of inadequate heating or cooling performance. Inspect filters at least every two months, more often if necessary due to local conditions and usage.

Discard dirty throwaway filters and replace with new, clean filters.

Disposable return air filters are supplied with this unit. See the unit Specification Sheet or Technical Manual for correct size and part number. To remove filters, access the filter access panel on the return side of the unit.

Cabinet Finish Maintenance

Use a fine-grade automotive wax on the cabinet finish to maintain its original high luster, especially in areas with extended direct sunlight.

Clean Outside Coil (Qualified Servicer Only)

Inspect the outside coil annually and clean as frequently as necessary to keep finned areas free of lint, hair, and debris.

Condenser And Induced Draft Motors

Bearings on condenser fan motors and the combustion fan motor are permanently lubricated. No additional oiling is required.

Flame Sensor (Qualified Servicer Only)

A drop in flame current can be caused by a nearly invisible coating on the flame sensor (from fuel or combustion air supply). This coating can be removed by carefully cleaning the flame sensor with steel wool.

NOTE: After cleaning, the microamp signal should be stable and in the range of 4 - 6 microamps DC.

Flue Passages (Qualified Servicer Only)

At the start of each heating season, inspect and, if necessary, clean the unit flue passage.

Lubrication

Fan shaft bearings, supply fan motors, condenser fan motors, and compressors are permanently lubricated.

Inspection & Cleaning

Examine all flue product carrying areas, the vent system, and main burners by a qualified service agency. Clean if necessary before each heating season for continued safe operation. Pay attention to deterioration from corrosion or other sources.

Examination procedure:

1. Disconnect power to the unit and remove the furnace section access panel.
2. Remove the burner assembly:
   • Disconnect wires from the gas valve, noting terminal connections.
   • Disconnect wires from the flame rod and ignition electrode.
   • Disconnect the gas piping at the union.
   • The entire burner assembly can now be removed.

NOTE: Use all removed screws; they are necessary for safe and proper unit operation.

3. Inspect and periodically clean the vent outlet (bird screen) on the access panel.

NOTE: Periodic check of operation and a log of CO² measurements are recommended to determine furnace efficiency or if cleaning is required.

WARNING

To avoid personal injury or death due to electric shock, do not remove internal compartment covers or attempt adjustments. Contact a qualified servicer immediately if abnormal operation occurs.

Functional Parts

Refer to the unit Parts Catalog for functional parts. Parts are available from your distributor.

TROUBLESHOOTING

Ignition Control Error Codes

The following lists probable causes of questionable unit operation. Refer to the Diagnostic Indicator Chart for signal interpretation and this section for explanations.

Remove the control box access panel and note the number of diagnostic LED flashes.

Fault Recall

The ignition control has a momentary push-button to display the last five detected faults on the diagnostic LED. Anytime the control is powered, fault code history can be retrieved by pressing and releasing the button once (less than 5 seconds); the LED will flash the Fault Code History (up to 5 codes, newest to oldest).

Fault code history is retained between power cycles until cleared. A fault code is added to the log if it differs from the most recent item. If the log is full, the oldest entry is dropped, and new faults are added.

NOTE: Do not hold the button for longer than 5 seconds. Holding it for 5 seconds or more will erase the memory!

Abnormal Operation - Heating Codes

Resetting From Lockout

An external lockout occurs if the ignition control determines that measurable combustion cannot be established within three consecutive ignition attempts. If flame is not established within the 4-second trial for ignition, the gas valve de-energizes, a 30-second inter-purge cycle completes, and ignition is re-attempted. This repeats three times. If combustion is not established, the control shuts off the induced draft blower and enters a lockout state.

If flame is established but lost, the control energizes the circulator blower at heat speed and begins a new ignition sequence. If flame is subsequently lost, the control recycles the ignition sequence.

A diagnostic fault code of 1 flash indicates lockout due to failed ignition attempts. The control resets automatically after one hour, or it can be reset by removing the thermostat signal or disconnecting electrical power for over five seconds.

IMPORTANT NOTE: Frequent resetting indicates a problem that needs correction. Contact a qualified servicer.

Pressure Sensor

The pressure sensor is in the control box, connected to the induced draft blower. It regulates blower speed to maintain proper air-fuel ratio for clean combustion. The electrical output signal is proportional to the differential pressure between the inducer inlet negative pressure and ambient air pressure. The sensor also guards against insufficient airflow (combustion air and flue products) through the heat exchanger.

At the start of a heat call, the control checks the pressure sensor output for proper null offset. If the output is outside the acceptable range, the control enters a 5-minute lockout. After the timer expires, normal operation resumes.

During inducer operation (except null test), the control monitors pressure sensor output for expected values. If a pressure sensor span error occurs, the control enters a 5-minute lockout. Normal operation resumes after the timer expires.

Primary Limit

The primary limit opens due to excessive supply air temperatures, potentially caused by a dirty filter, excessive duct static, insufficient airflow, or a faulty limit. Check filters, duct static, blower motor, and blower motor speed tap. This limit automatically resets when temperature falls below a preset level.

If a limit switch opens, the gas valve immediately de-energizes, and the induced draft and air circulating blowers energize. They remain energized for 5 minutes or until the limit switch recloses, whichever occurs first.

NOTE: If the primary limit opens three (3) times within the same call for heat, the ignition control will lock out for one (1) hour with the air circulating blower energized at heating speed.

Flame Detected with Gas Valve Closed

If flame is detected with the gas valve de-energized, the combustion and air circulator blowers energize. The control can be reset by removing power or will auto-reset after one hour. Miswiring is a probable cause. The initial lockout period is 5 minutes. The control continues to monitor the flame sense input and resumes normal operation when flame is no longer sensed.

Low Flame Signal

Under some conditions, fuel or air supply can create a nearly invisible coating on the flame sensor, acting as an insulator and causing a drop in the flame signal. If the signal drops below a predetermined value, the ignition control displays an error code (1) flash on the amber diagnostic LED. The unit operates until flame can no longer be detected.

Burner Switch

The burner temperature switch, mounted on the burner assembly, monitors burner box temperature. It is normally closed (electrically) and auto-resets. This switch guards against burner flames not being properly drawn into the heat exchanger.

The control senses an open blocked burner switch, indicating burner temperature/pressure exceeded its set point. The control de-energizes the gas valve, energizes the inducer for pre-purge, and energizes the indoor blower. The initial lockout period is five minutes. After this, the control evaluates the blocked burner switch state. If closed, normal operation resumes. If the switch fails to reset before the recovery timer expires, the control enters a one-hour lockout state.

ID Plug

Control operational parameters are stored in the ID Plug connected to the circuit board. A valid ID plug is required for heating mode operation. Without it, the control will not respond to a heat call but will respond to thermostat inputs "Y" or "G" for fan operation. Cooling delays are ignored. The control enters hard lockout and will not respond to heating requests until power is cycled with a valid ID plug installed.

NOTE: Some electronic thermostats have a built-in compressor short cycle timer that may be longer than the 3-minute delay. If the compressor has not started after 3 minutes, wait an additional 5 minutes for the thermostat's short cycle delay.

The furnace control status light can guide troubleshooting. Some useful status light codes are below:

'The fault condition must be cleared for 30 seconds before normal operation can resume. A power cycle will also reset any lockout.

APPENDIX A BLOWER PERFORMANCE DATA

Tables provide blower performance data for 3 Ton, 4 Ton, and 5 Ton models (DRG036, DRG048, DRG060) under various External Static Pressures (ESP), SCFM, RPM, and BHP for Down Flow and Horizontal Flow configurations. Burner inputs are listed.

Shaded areas indicate air flow below recommended levels for High Stage cooling or heating.

APPENDIX B ELECTRICAL DATA

A table lists electrical data for various Daikin DRG models, including Electrical Rating, Compressor specifications (RLA, LRA), Outdoor Fan Motor (HP, FLA, Type), Indoor Fan Motor (HP, FLA, Part #), Optional Electric Heat (KW*, FLA), Optional Powered Convenience (FLA), and Power Supply (MCA, MOP).

APPENDIX C UNIT DIMENSIONS

Diagrams show unit dimensions and duct opening sizes. Model Size (3 TON, 4 & 5 TON) and DIM "A" are provided. Bottom view details supply (12" x 17") and return (11" x 25") duct openings, drain location, and utility access.

APPENDIX D MIN-MAX AIRFLOW

A table lists recommended minimum and maximum airflow ranges (SCFM) for Heating and Cooling for DRG units (DRG036, DRG048, DRG060) based on Fire Rate (BTU/HR).

WIRING DIAGRAM

Detailed wiring diagrams are provided for DRG models, including power and controls wiring. A component legend and wire code list are included. Warnings about high voltage are prominently displayed.

Start-up Checklist

Pre Start-Up items are listed for checking during installation, including verification of packaging removal, shipping brackets, job site voltage, condensate connection, clearances, weatherproofing, flue screen, gas piping, gas pressure, fan/pulley security, belt tension, refrigerant piping, wiring, electrical connections, crankcase heater energization, compressor rotation, accessory installation, filter status, and thermostat installation.

Fields are provided to record values during Start-Up: Electrical (Supply Voltage, Compressor Amps, Blower Amps, Condenser Fan Amps), Blower External Static Pressure (Return Air, Supply Air, Total External, Blower Wheel RPM), Temperatures (Outdoor, Return, Cooling Supply, Heating Supply), and Pressures (Gas Inlet, Gas Manifold, Suction, Superheat, Discharge, Subcooling).

CUSTOMER FEEDBACK

Daikin is interested in product comments. Please fill out the feedback form at https://daikincomfort.com/contact-us. A QR code is also provided to direct users to the feedback page.

Our continuing commitment to quality products may mean a change in specifications without notice.

©2020-2021 DAIKIN MANUFACTURING COMPANY, L.P.
19001 Kermier Rd., Waller, TX 77484
www.daikincomfort.com