White Rodgers 1F79 Non-Programmable Heat Pump Thermostat

Contents

• Preparations
• Thermostat Details
• Removing Old Thermostat
• Mounting and Wiring
• Check Thermostat Operation
• Specifications
• Troubleshooting

1. Preparations

Assemble tools required as shown below:

• Hand or Power Drill with 3/16 inch drill bit (if needed)
• Flat blade screwdriver
• Wire cutter/stripper
• Spirit level or plumb bob and line (optional - thermostat does not need to be level to work properly)

Failure to follow and read all instructions carefully before installing or operating this control could cause personal injury and/or property damage.

Your Thermostat Replaces

2. Thermostat Details

Thermostat Base Components:

• Mounting holes
• W905, W904 terminals
• W906 for Emergency Heat Second Stage
• Clip for Slow Cycle (current location)
• Clip for Celsius (current location)
• W904 & W905 (location on earlier models)
• O/B Terminal
• Fan Control
• Terminal Switches Selection

Figure 1 shows the thermostat base with its components.

3. Removing Old Thermostat

ATTENTION! This product does not contain mercury. However, this product may replace a unit which contains mercury. Do not open mercury cells. If a cell becomes damaged, do not touch any spilled mercury. Wearing non-absorbent gloves, take up the spilled mercury and place into a container which can be sealed. If a cell becomes damaged, the unit should be discarded. Mercury must not be discarded in household trash. When the unit this product is replacing is to be discarded, place in a suitable shipping container. Refer to www.thermostat-recycle.org for location to send the product with mercury.

1. Remove Old Thermostat: A standard heat/cool thermostat consists of three basic parts: the cover, the base, and the switching subbase.
2. CAUTION: To prevent electrical shock and/or equipment damage, disconnect electrical power to the system at the main fuse or circuit breaker until installation is complete.
3. Before removing wires from old thermostat's switching subbase, label each wire with the terminal designation it was removed from.
4. Remove the front cover of the old thermostat. With wires still attached, remove the wall plate from the wall. If the old thermostat has a wall mounting plate, remove the thermostat and the wall mounting plate as an assembly.
5. Identify each wire attached to the old thermostat using the labels enclosed with the new thermostat.
6. Disconnect the wires from the old thermostat one at a time. DO NOT LET WIRES FALL BACK INTO THE WALL.
7. Install new thermostat using the following procedures.

CAUTION: Take care when securing and routing wires so they do not short to adjacent terminals or rear of thermostat. Personal injury and/or property damage may occur.

Attach Thermostat Base to Wall

1. Remove the packing material from the thermostat. Gently pull the cover straight off the base. Forcing or prying on the thermostat will cause damage to the unit.
2. Connect wires beneath terminal screws on base using appropriate wiring schematic (see figures 2 through 4).
3. Place base over hole in wall and mark mounting hole locations on wall using base as a template.
4. Move base out of the way. Drill mounting holes.
5. Fasten base loosely to wall, as shown in figure 1, using two mounting screws. Place a level against bottom of base, adjust until level, and then tighten screws. (Leveling is for appearance only and will not affect thermostat operation.) If you are using existing mounting holes, or if holes drilled are too large and do not allow you to tighten base snugly, use plastic screw anchors to secure subbase.
6. Push excess wire into wall and plug hole with a fire-resistant material (such as fiberglass insulation) to prevent drafts from affecting thermostat operation.

Battery Location

This thermostat does not require batteries to operate. The 2 "AAA" alkaline batteries are for the thermostat to remember the configuration menu selections if AC voltage is lost. If the display shows BATT or CHANGE ⛛ when AC power is not present, the batteries are low and should be replaced with fresh "AAA" Energizer alkaline batteries. For best results, replace all batteries with new premium brand alkaline batteries such as Duracell® or Energizer®. To replace the batteries, install the batteries along the top of the base (see fig. 1). The batteries must be installed with the positive (+) ends to the right.

4. Mounting and Wiring

Electric/Gas Jumper (Fan Option)

• If your emergency or auxiliary system will energize the blower, then jumper W906 on the thermostat base must be cut (see fig. 1).
• If your emergency or auxiliary heat system requires that the thermostat energize the fan circuit, do not cut jumper W906.
• If you are unsure of your application, contact a qualified service person.

°F or °C Selection

The factory default setting for temperature display is Fahrenheit. If you want the temperature in Celsius, clip jumper W904.

Fast or Slow Cycle Selection

The factory default setting is fast cycle, which cycles 1st stage at approximately 1.2°F and 2nd stage 0.75°F. If you prefer slow cycle, clip jump W905. The 1st stage and 2nd stage would be 1.5°F and 1.2°F respectively.

O/B Terminal Switch Selection

The O/B switch on this thermostat is factory set to "O" position. This will accommodate the majority of heat pump applications, which require the changeover relay to be energized in COOL. If the thermostat you are replacing or the heat pump being installed with this thermostat requires a “B” terminal, to energize the changeover relay in HEAT, the O/B switch must be moved to the “B” position.

NOTE: If safety circuits are in only one of the systems, remove the transformer of the system with NO safety circuits.

Figure 2 shows a typical wiring diagram for single transformer systems.

Figure 3 shows a typical wiring diagram for two transformer systems with NO safety circuits.

NOTE: Polarity must be observed. If the HOT side of the second transformer is jumpered to the COMMON side of the first transformer a short will be made. Damage to equipment will occur when power is restored.

Figure 4 shows a typical wiring diagram for two transformer systems with safety circuits in BOTH systems.

Wiring Diagram Descriptions:

• Figure 2 (Single Transformer): Shows connections for Changeover Relay, Compressor Contactor, Fan Relay, Aux Relay (Stage 2), Emergency Relay, System Monitor Switch, and Transformer (Class II). Notes indicate when the Changeover Relay is energized and jumper requirements for Aux Heat.
• Figure 3 (Two Transformers, No Safety Circuits): Includes CUT AND TAPE OFF instruction. Shows connections for Changeover Relay, Compressor Contactor, Fan Relay, Emergency Relay, Aux Relay (Stage 2), System Monitor Switch, and two Transformers (Class II). Notes indicate that two commons must be jumpered together and changeover relay energization.
• Figure 4 (Two Transformers, Safety Circuits in BOTH Systems): Shows connections for Changeover Relay, Compressor Contactor, Fan Relay, Emergency Relay, Aux Relay (Stage 2), System Monitor Switch, Accessory Relay, and two Transformers (Class II). Notes indicate that two commons must be jumpered together, changeover relay energization, and the accessory relay scheme requirement.

5. Check Thermostat Operation

NOTE: To prevent static discharge problems, touch side of thermostat to release static build-up before touching any keys. If at any time during testing your system does not operate properly, contact a qualified serviceperson.

Fan Operation

1. Turn on power to the system.
2. Move fan switch to ON position. The blower should begin to operate.
3. Move fan switch to AUTO position. The blower should stop immediately.

CAUTION: Do not allow the compressor to run unless the compressor oil heaters have been operational for 6 hours and the system has not been operational for at least 5 minutes.

Heating System

1. Move SYSTEM switch to HEAT position. If the auxiliary heating system has a standing pilot, be sure to light it.
2. Press ⬆ to adjust thermostat setting to 1° above room temperature. The heat pump system should begin to operate. However, if the Flame icon (?) and Snowflake icon (❄️) are flashing, the compressor lockout feature is operating (see Configuration menu, item 3.)
3. Adjust temperature setting to 4º above room temperature. The auxiliary heat system should begin to operate and the Flame icon (?) will be flashing.
4. Press ⬇ to adjust thermostat setting below room temperature. The heating system should stop operating.

Emergency System

EMER bypasses the Heat Pump to use the heat source wired to terminal E on the thermostat. EMER is typically used when compressor operation is not desired, or you prefer back-up heat only.

1. Move SYSTEM switch to EMER position. EMER will flash on the display.
2. Press ⬆ to adjust thermostat setting above room temperature. The Aux heating system will begin to operate. The Flame icon (?) will display flashing to indicate that the Aux system is operating.
3. Press ⬇ to adjust the thermostat below room temperature. The Aux heating system should stop operating.

CAUTION: To prevent compressor and/or property damage, if the outdoor temperature is below 50°F, DO NOT operate the cooling system.

Cooling System

1. Move SYSTEM switch to COOL position.
2. Press ⬇ to adjust thermostat setting below room temperature. The blower should come on immediately on high speed, followed by cold air circulation.
3. Press ⬆ to adjust temperature setting above room temperature. The cooling system should stop operating.

Thermostat Buttons and Switches:

• 1 (Up arrow ⬆): Raises temperature setting.
• 2 (Down arrow ⬇): Lowers temperature setting.
• 3 FAN switch: (ON, AUTO)
• 4 SYSTEM switch: (COOL, OFF, HEAT, EMER)

The Display

• 5 Indicates a malfunction with the system.
• 6 Flame icon (?): Displayed when the SYSTEM switch is in the HEAT position. Flame icon (?) is displayed flashing when 2nd-stage heat (Aux or Emergency) is energized. Snowflake icon (❄️) is displayed (non-flashing) when the SYSTEM switch is in the COOL position. Snowflake and Flame icons are displayed (flashing) if the thermostat is in lockout mode to prevent the compressor from cycling too quickly.
• 7 EMER: Displayed flashing when the system switch is in EMER position.
• 8 Displays current temperature.

Before you begin programming your thermostat, you should be familiar with its features and with the display and the location and operation of the thermostat buttons. Your thermostat consists of two parts: the thermostat cover and the base. To remove the cover, gently pull it straight out from the base. To replace the cover, line up the cover with the base and press gently until the cover snaps onto the base.

Figure 5 shows the thermostat display, buttons, and switches.

Configuration Menu

The configuration menu allows you to set certain thermostat operating characteristics to your system or personal requirements. To enter the configuration menu, with SYSTEM switch in OFF position, hold ⬆ and ⬇ for at least two seconds. To exit the configuration menu, move the SYSTEM switch from the OFF position.

Configuration Menu Steps:

* Not available on earlier models

Additional Configuration Notes:

• When SYSTEM switch is in the OFF position, the display shows the currently programmed set temperature (this is blank when SYSTEM switch is in the OFF position).
• “BATT” or “CHANGE” ⛛ is displayed when 2 "AAA" batteries are low and should be replaced.
• In the run mode, if the setpoint temperature is manually raised by 3°F (2°C) or more above the actual temperature with the TEMPERATURE UP key, and the fast second stage feature is enabled (FA on), the second stage will energize immediately. With FA off, second stage will not energize until the setpoint temperature is 1°F or more above actual temperature for more than ten minutes.
• Select Compressor Lockout (CL): Selecting CL ON will cause the thermostat to wait 5 minutes before turning on the compressor if the heating and cooling system loses power. It will also wait 5 minutes minimum between cooling and heating cycles. This is intended to help protect the compressor from short cycling. Some newer compressors already have a time delay built in and do not require this feature. Your compressor manufacturer can tell you if the lockout feature is already present in their system. When the thermostat compressor time delay occurs it will flash the Snowflake (❄️) and Flame (?) Icons for about five minutes.
• Select Temperature Display Adjustment (3 LO to 3 HI): Allows you to adjust the room temperature display up to 3° higher or lower. Your thermostat was accurately calibrated at the factory but you have the option to change the display temperature to match your previous thermostat. The current or adjusted room temperature will be displayed on the left side of the display.
• Select Backlit Display: (Not available on earlier models) The display backlight improves display contrast in low lighting conditions. Selecting backlight ON will keep the light on continuously. Selecting Backlight OFF will keep the light off.

6. Specifications

ELECTRICAL DATA

• Electrical Rating: 20 to 30 VAC 50/60 Hz.
• 0.05 to 1.0 Amps (Load per terminal)
• 1.5 Amps Maximum Total Load (All terminals combined)

THERMAL DATA

• Setpoint Temperature Range: 45°F to 90°F (7°C to 32°C)
• Operating Ambient Temperature Range: 32°F to 105°F
• Operating Humidity Range: 0 to 90% RH (non-condensing)
• Shipping Temperature Range: -40°F to 150°F

7. Troubleshooting

Reset Operation

If a voltage spike or static discharge blanks out the display or causes erratic thermostat operation you can reset the thermostat by pressing ⬆ and ⬇ at the same time when system is switched from "OFF" to "HEAT" position. This also resets the factory defaults. If the thermostat has power, has been reset and still does not function correctly contact your heating/cooling service person or place of purchase.

Batteries

For optimum performance, we recommend replacing batteries once a year with fresh "AAA" alkaline batteries.