Winco SPECTRUM Gas Countertop Equipment Thermostatic (TSTAT) Griddles

Product Overview & Specifications

Congratulations on your purchase of this Winco SPECTRUM™ equipment. This manual provides essential instructions for safe operation, installation, and maintenance to ensure years of reliable performance.

Models Covered:

• NGGD-12T
• NGGD-24T
• NGGD-36T
• NGGD-48T

Form Number: NGGD-T Manual - 07/2025

Important Information for Future Reference

Please complete the following details and retain this manual for the life of the equipment. This information is required for service and/or parts.

Model Number: _________________________

Serial Number: _________________________

Date Purchased: _________________________

Safety Precautions and Warnings

❗ DANGER: Imminent hazard that will result in serious injury or death.

⚠️ WARNING: Potential hazard or unsafe practice that could result in serious injury or death.

⚠️ CAUTION: Potential hazard or unsafe practice that could result in minor or moderate injury or product or property damage.

ℹ️ NOTICE: Information that needs special attention or must be fully understood, even though not dangerous.

⚠️ WARNING: For your safety, do not store or use gasoline or other flammable vapors or liquids near this or any other appliance. Keep the area free and clear of combustibles. (See ANSI Z83.14B, 1991).

⚠️ WARNING: Improper installation, adjustment, alteration, service, or maintenance can cause property damage, injury, or death. Read installation, operating, and maintenance instructions thoroughly before installing or servicing.

⚠️ WARNING: Instructions must be posted in a prominent location. All safety precautions must be taken if gas is smelled. Safety information is available from your local gas supplier.

⚠️ CAUTION: These models are designed, built, and sold for commercial use only. If positioned for public use, ensure cautions, warnings, and operating instructions are clearly posted near each unit.

⚠️ WARNING: A factory-authorized agent should handle all maintenance and repair. Contact your authorized service representative before performing any maintenance or repair.

Gas Pressure: The appliance and its shutoff valve must be disconnected from the gas supply piping system during pressure testing of that system at pressures exceeding 1/2 psi (3.45 kPa). For testing at or below 1/2 psi (3.45 kPa), isolate the appliance by closing its manual shut-off valve.

ℹ️ NOTICE: This product is intended for commercial use only. Not for household use.

ℹ️ NOTICE: Local codes regarding installation vary. Installation must comply with all local codes, including NFPA 96.

Introduction

This manual guides you through the proper operation and maintenance of your Winco SPECTRUM™ griddle. Following these instructions ensures optimal performance and longevity. Winco is not liable for issues arising from incorrect manual adherence, unauthorized tampering, use of non-original parts, improper handling or cleaning, or user-inflicted damage.

Data Plate Location: The data plate is located on the rear or side panel of the unit.

Shipping Damage Inspection: Examine all containers for damage before and during unloading. Claims for apparent damage must be noted on the freight bill at delivery and signed by the carrier representative. Concealed damage requires an inspection request to the carrier within 15 days of receipt. Keep all packaging materials.

Installation must be performed by a qualified installer who understands these instructions. For questions regarding installation, operation, maintenance, or service, contact WINCO®.

Package Contents & Unpacking

Package Contents:

• (1) Griddle Set
• (1) Grease Drawer
• (4) Adjustable Legs
• (1) Natural to LP Gas Conversion Kit

Unpacking the Equipment:

1. Dispose of all packaging materials responsibly.
2. Remove all packing materials, tape, protective plastic, and cardboard from the unit.
3. Clean any glue residue from plastic or tape.
4. Ensure the countertop can support the griddle's weight.
5. Place the unit in the desired position and height.

Note: Save the original box and packaging for potential future shipping or service needs.

Remember to remain alert, train operators properly, and use common sense when operating this equipment.

Installation

Follow these instructions carefully to prevent injury.

Installation Codes and Standards

Installation must comply with:

• State and local codes.
• National Fuel Gas Code, ANSI Z223.1/NFPA #54 (latest edition), including NFPA #54 Section 10.3.5.2 for Venting.
• NFPA Standard #96 Vapor Removal from Cooking Equipment (latest edition).
• In Canada: Local codes, CAN/CSA-B149.1 (Natural Gas) and CAN/CSA-B149.2 (Propane) Installation Codes.

To Reduce Risk of Injury or Damage:

1. Read this manual thoroughly before installation and operation. Contact your representative if you have questions.
2. Remove the griddle from packaging and clean off all protective plastics and residues.
3. Place the griddle on a firm, level surface. Consult local standards for positioning, spacing, and ventilation.
4. Ensure the gas supply type matches the unit's nameplate.

? WARNING: Burn Hazard. The appliance is hot during operation. Use caution when touching.

Leg Installation

1. Attach adjustable legs by screwing them into the recess nuts at each corner of the unit frame.
2. Level the unit by turning the feet clockwise or counter-clockwise.

Gas Pressure Regulator Installation

1. The gas regulator is preset for 4" Water Column (W.C.) for Natural Gas and 10" W.C. for L.P. Propane Gas. Minor adjustments may be needed based on site pressure.
2. Install the regulator close to the griddle on the gas supply line. Ensure the arrow on the regulator points in the direction of gas flow, and the vent plug and adjustment screw are upright (refer to diagrams).
3. Minimum supply pressure should be 7"-9" W.C. for Natural Gas and 10"-12" W.C. for L.P. Propane Gas. Never connect to a supply pressure greater than 1/2 psig (3.45 kPa) or 14" W.C.

Diagram Description: Figure 1 shows the regulator with an arrow indicating gas flow direction. Figure 2 shows the correct upright orientation of the vent plug and adjustment screw.

Leveling

Proper leveling ensures even temperature distribution. Use a level on the griddle surface.

1. Adjust legs by turning the bullet feet. Turn counter-clockwise to increase height, clockwise to decrease.
2. Do not extend legs more than 1-3/4".

Ventilation Hood

Install the griddle under a suitable ventilation hood for safe operation and proper ventilation. Keep the space between the griddle and hood clear of obstructions.

? WARNING: Fire Hazard. Follow correct installation procedures and regulations. Operation and safety training are essential. Installation must be by qualified personnel. Hood and fire suppression systems require maintenance. Only qualified personnel should use this equipment.

Installation (Continued)

Gas Connection

1. Verify the gas type on the unit's data plate and do not connect to any other gas type. Gas supply connections and pipe joint compounds must be resistant to propane.
2. Purge the supply line to remove dust, dirt, or foreign matter before connecting.
3. A gas shut-off valve is required in the gas line ahead of the griddle. The supply line must be at least 3/4" iron pipe equivalent.
4. Install the supplied pressure regulator outside the broiler. Standard orifices are set for 4" W.C. (Natural Gas) / 10" W.C. (L.P. Propane). Use the 1/8" pipe tap on the burner manifold for pressure checks. Ensure gas piping is clean and free of obstructions.
5. An adequate gas supply is crucial. Undersized or low-pressure lines restrict gas volume. Recommended minimum supply pressure is 7"-9" W.C. for Natural Gas and 10"-12" W.C. for L.P. Propane. Manifold pressure should not drop significantly when all units operate simultaneously.
6. Gas Supply Piping System Testing:
• If test pressures exceed 1/2 psig (3.45 kPa), disconnect the griddle and its shutoff valve from the system.
• If test pressures are 1/2 psig (3.45 kPa) or less, isolate the griddle by closing its manual shut-off valve during testing.

⚠️ WARNING: Do not use an open flame to check for leaks. Use a soap and water solution.

To Avoid Serious Personal Injury:

• Always install in a well-lit, spacious work area.
• Operate only on a solid, level, nonskid surface.
• Never bypass, alter, or modify the equipment. Doing so creates hazards and voids the warranty.
• Never operate the unit without all warnings attached.

Clearances and Ventilation

Installation Surfaces: These units are suitable for installation on non-combustible surfaces only.

• Combustible Clearances: 6" sides, 6" rear, 4" floor.
• Noncombustible Clearances: 0" sides, 6" rear, 4" floor.

? THIS EQUIPMENT GETS EXTREMELY HOT! Do not position or operate near combustible or flammable objects.

Do not obstruct airflow under the unit (legs) or behind the unit (flue). Ensure adequate clearance for combustion and ventilation air openings. Do not place objects between the unit bottom and the countertop. Ensure clearance for front panel removal.

Conversion to Propane Gas

Griddles are shipped with orifices for natural gas. Propane conversion parts (burner and pilot orifices) are included. It is recommended that a trained gas service technician perform the conversion.

1. Remove the front panel.
2. Remove burners from orifice hoods by unscrewing mounting screws and sliding burners off.
3. Remove natural gas orifice hoods and install the furnished propane hoods.
4. Reinstall burners.
5. Reinstall the front panel.
6. Remove the plug from the pressure regulator, invert it, and reinstall. The "LP or NAT" indicator should be visible. LP units are set for 10" W.C., NAT units for 6" W.C.
7. For LP Gas, set manifold pressure to 10" (25.4cm) W.C. A 1/8" pipe plug on the supply pipe can be used for gauge attachment.

⚠️ WARNING: Check all gas supply line joints for leaks using soap and water solution before lighting. Do not use an open flame.

Calibration

Each thermostat controls a 12" zone. Use a surface probe thermometer to measure temperatures at specific points:

• Measure at the center points of the cooking zones, located 6" from the side splash and every 12" across the width, 12" back from the front edge.
• Note: Infrared thermometers are not recommended due to sensitivity to surface color and angle.

1. Set thermostats to 350°F and allow the unit to stabilize, cycling burners ON and OFF at least twice.
2. After the burner cycles OFF, measure the zone temperature. It should be 350°F ±15°F.
3. If adjustment is needed:
• Carefully loosen the knob set screw (do not turn the knob itself).
• Remove the knob to expose the temperature dial.
• Loosen the temperature dial screws and adjust the dial so the knob's arrow aligns with the griddle plate temperature reading. Reinstall the knob to verify.
4. IMPORTANT: Never adjust the screw in the center of the thermostat shaft, as this will ruin calibration.
5. Once calibrated, tighten the temperature dial screws and knob set screws.

Diagram Description: A diagram shows measurement points on the griddle surface: 6" from the side, then every 12" across, and 12" from the front edge.

Lighting Instructions

The pilot light is factory-set. A screwdriver may be needed for initial adjustment based on elevation.

Lighting Pilot

1. Turn off the manual gas valve and wait 5 minutes to clear any gas.
2. Turn all burner knobs to "OFF".
3. Hold an ignition source (e.g., lit match) to the pilot. Once the flame is established, remove the ignition source. Adjust pilot flame height using the pilot valve screw if necessary.
4. Turn burner knobs to "ON". If a burner doesn't ignite, open the pilot valve slightly more. If the pilot flame is too large, reduce it. The pilot flame should be just large enough for reliable burner ignition.

Lighting Main Burner

Turn the burner knob to "ON", then adjust to the desired flame level. Adjustment is infinite between "ON" and "OFF".

Main Burner Air Supply

For efficient combustion, ensure a proper balance of gas volume and primary air. Insufficient air causes a yellow, streaming flame.

1. Primary air is controlled by an air shutter on the front of the burner.
2. Loosen the screws on the burner front and adjust the air shutter to just eliminate yellow tips on the burner flame. Tighten screws to lock the shutter.

⚠️ CAUTION: Clean the regulator monthly, ensuring the vent opening is clear. Blocked vents cause pressure variations and affect performance.

⚠️ CAUTION: Never attempt to move a grill section while cooking. Turn off the unit, let it cool, and use protective gloves. Do not block the space between the legs, as this is for combustion air.

Burners are lit from constantly burning pilots. Simply turn the valve to the desired flame height. Avoid fans blowing directly at the unit or open windows nearby. Ensure adequate room ventilation to compensate for air removed by ventilation systems.

All valves require periodic checking and lubrication by an authorized service representative.

Safety

• Repairs must be performed by a WINCO® Approved Service Technician.
• Do not remove components or service panels.
• Allow the unit to cool before cleaning.
• Do not use hose or pressure washing for cleaning.
• If damaged, the unit must be repaired by a WINCO Approved Qualified Service Technician.

Operation

Before operating, ensure the griddle is level. Adjust feet as needed.

Note: A metal-burning smell may occur during initial use; this is normal and will decrease. The griddle and parts get very hot; use caution.

Controls: Each burner is controlled by heavy-duty infinite control valves, with an input of 30,000 BTU/h.

Cleaning, Care & Maintenance

⚠️ CAUTION: Use only non-abrasive cleaners. Abrasive cleaners can scratch the finish. Avoid steel wool, chlorine, iodine, ammonia, or bromine chemicals, as they can damage stainless steel and glass materials.

Initial Cleaning

Before operation, wash the griddle plate and exterior with a mild detergent or soap solution. Do not use abrasive cleaners. If stainless steel surfaces discolor, clean gently in the direction of the grain.

Seasoning the Griddle

1. Heat the griddle to 300-350°F (150-180°C).
2. Apply a small amount of cooking oil (approx. 1 oz per sq ft) to the griddle plate.
3. Spread oil thinly with a cloth, creating a film. Wipe off excess oil.
4. Repeat 2-3 times until a slick, mirror-like surface is achieved.

Daily Cleaning

1. Turn off the unit and allow it to cool completely before cleaning.
2. Clean the back, sides, top, and front of the unit.
3. Clean trivets daily.
4. Empty and clean the grease drawer daily.

Weekly Cleaning

1. Clean the unit thoroughly. Clean stainless steel or chromed surfaces with a damp cloth and polish with a dry cloth. Detergents may be used. Use a non-abrasive cleaner for discolorations.
2. Keep burner air shutter openings and main burner ports clean. Use a wire brush for stainless steel burners or a sharp-pointed metal instrument for gas ports to ensure open ports.

Troubleshooting

If the griddle is not operating properly, consult the following table before calling for service.

Service and Repair

This equipment must only be serviced by an authorized agent. Parts adjustments must be made by an authorized service agent. For questions or problems, contact WINCO® customer service before sending the unit. Refer to the "Limited Warranty" on www.WincoUS.com.

Exploded View and Spare Parts

Exploded View (Model Shown: NGGD-24T):

Diagram Description: An exploded view diagram shows the griddle components with numbered parts corresponding to the spare parts list. The numbers indicate: 1. U-Shaped Pipe Burner, 2. Knob, 3. Grease Drawer, 4. Gas Pressure Regulator, 5. #42 Natural Orifice, 6. #53 LP Orifice, 7. Pilot Tube, 8. Thermostat Valve, 9. Pilot Valve, 10. Adjustable Leg.

Spare Parts List

To Order Parts: Scan the QR code or visit https://www.wincous.com/pages/order-parts.