936RX

Overview

The Vulcan Hart 936RX is a heavy-duty gas countertop griddle for commercial kitchens. Its 36-inch-wide cooking surface measures 36 x 24 inches and is made from 1-inch-thick polished steel. Three independently controlled 12-inch sections let operators set different temperatures across the plate for menu items with different cooking requirements.

The 936RX belongs to Vulcan’s 900RX series. Its electric ignition system is controlled by a momentary power switch: the igniters receive power only while the switch is held in the ON position. Pilot thermocouples and safety valves monitor the pilots. If a pilot goes out, the safety valve shuts off gas to the pilot and main burners.

The supplied service manual is intended for trained Vulcan service technicians. Installation and gas-pressure work should be handled by a trained gas service technician, as recommended in the installation and operation manual.

Key Features

• Three cooking zones: One mechanical snap-action thermostat and one 27,000 BTU/hr U-shaped aluminized steel burner serve each 12 inches of griddle width.
• Polished steel plate: The 1-inch-thick plate provides a flat cooking surface. The product listing identifies the shown top as steel; this description does not identify the unit as a chrome-top configuration.
• Commercial construction: Stainless steel front, sides and front top ledge, with a fully welded stainless and aluminized steel body frame.
• Grease management: A 3½-inch-wide stainless steel grease trough and a fully welded grease chute help direct grease and prevent migration.
• Back and side protection: A 4-inch stainless steel backsplash and tapered side splashes are listed for the griddle.
• Thermostatic control: Each section has a mechanical snap-action thermostat with a stated operating range of 200°F to 550°F. Chrome thermostat knob guards are specified in the service manual.
• Electric ignition and pilot safety: The 900RX system has spark ignition, pilot thermocouples and pilot safety valves. The momentary switch powers the igniters only while held.

Specifications

• Manufacturer: Vulcan Hart.
• Model: 936RX.
• Equipment type: Heavy-duty gas countertop griddle.
• Item number: 901936RX24CL.
• VPN: 936RX-101.
• UPC: 400014100312.
• Cooking surface: 36 inches wide x 24 inches deep.
• Published dimensions: 36 inches wide x 24 inches deep x 15¼ inches high. The service manual also describes an 11-inch low-profile cooking height on 4-inch legs.
• Griddle plate: 1-inch-thick polished steel.
• Burners: Three U-shaped aluminized steel burners, one per 12-inch section.
• Input: 27,000 BTU/hr per burner; 81,000 BTU/hr total.
• Thermostats: Mechanical snap-action controls with a 200°F to 550°F operating range.
• Body and exterior: Stainless steel front, sides and front top ledge; fully welded stainless and aluminized steel body frame.
• Back and sides: 4-inch stainless steel backsplash and tapered side splashes.
• Grease components: 3½-inch-wide stainless steel grease trough and fully welded grease chute.
• Electrical connection: 120V, 50/60Hz, 1 amp, single phase; NEMA 5-15 USA plug.
• Gas connection: ¾-inch rear gas connection; a gas pressure regulator is supplied and must be installed.
• Regulated manifold pressure: 4 inches W.C. for natural gas and 10 inches W.C. for propane, with all burners operating.
• Supply pressure upstream of regulator: 7–9 inches W.C. for natural gas and 11–12 inches W.C. for propane.
• Maximum gas supply pressure: The griddle must not be connected to supply pressure greater than ½ psig (3.45 kPa) or 14 inches W.C.

Installation & Requirements

Gas connection and regulator

The gas inlet is at the rear of the griddle and takes a ¾-inch NPT gas supply line. The supplied regulator must be installed on the gas supply line as close to the griddle as possible. Orient the arrow on the underside of the regulator in the direction of gas flow, and position the regulator with its vent plug and adjustment screw upright. Check and set the pressure after installation, with all burners on: the specified regulated pressure is 4 inches W.C. for natural gas or 10 inches W.C. for propane. Upstream supply pressure should be 7–9 inches W.C. for natural gas or 11–12 inches W.C. for propane. Do not connect the griddle to supply pressure above ½ psig (3.45 kPa) or 14 inches W.C.

The installation manual calls for a ¾-inch NPT gas supply line and says gas supply connections and joint compound must resist propane. Install a gas shutoff valve upstream of the griddle. Check gas-line joints for leaks with a soap-and-water solution, never an open flame. Purge gas lines fully after leak testing. For a supply pressure above ½ psig (3.45 kPa), disconnect the griddle and its individual shutoff valve from the piping system; at or below that pressure, isolate the griddle by closing its individual manual shutoff valve.

Electrical connection and ventilation

The 900RX ignition circuit requires 120V, 50/60Hz, 1 amp, single-phase power and has a NEMA 5-15 USA plug. The power switch operates the electric ignition system; it does not serve as the gas shutoff. The manual says flue gases should not be obstructed and recommends ventilation to the outside through a system installed by qualified personnel. It specifies a minimum 18-inch distance from the end of the flue to the filters of the hood venting system.

Operation

Lighting the pilots

For the 900RX lighting procedure, turn the griddle shutoff valve to OFF and wait 5 minutes so any gas that may have accumulated in the burner compartment can escape. Turn the shutoff valve ON. Hold the power switch in the ON position while pressing and holding the red button on the corresponding pilot safety valve. Watch the pilot through its sight hole. After the pilot has burned for about 45 seconds, release the safety-valve button. If the pilot does not stay lit, repeat the procedure and hold the button longer before releasing it. Repeat for each pilot. The manual notes that more time may be needed when first installing the unit or after the main gas supply has been off for an extended period; pilot adjustment may be needed to increase gas flow to the pilot.

If the electronic ignition system fails, the manual describes lighting the pilots with an outside ignition source while pressing the corresponding red safety-valve button, without holding the power switch. If the pilots do not light after following the procedure, turn the griddle shutoff valve OFF and contact an authorized service contractor.

Cooking and shutdown

Once the pilots are lit, turn each thermostat to the desired setting to operate its section. Each 12-inch section is controlled independently. To shut down the burners, turn the thermostats to OFF or turn the griddle shutoff valve OFF. If the shutoff valve remains ON, the pilots remain lit and monitored by the safety valve. Turning the griddle shutoff valve OFF cuts gas to the pilots and thermostats, so the pilots must be relit before the next use.

Cleaning & Maintenance

The griddle and its parts are hot during operation; use care when operating, cleaning or servicing it. The manual says to clean the cooking surface after each use according to the instructions for the particular surface finish, and to empty the grease drawer throughout the day as needed. The provided manual excerpt does not specify a surface-finish-specific cleaning method for this plate.

Once a day, when the griddle is cool, check the flue and clear obstructions. Thoroughly clean the backsplash, sides and front daily. Do not strike the backsplash with a spatula or other tool, as this can create a gap between it and the plate that is difficult to clean. Remove, empty and wash the grease drawer as an ordinary cooking utensil.

Once a week, clean the griddle surface thoroughly using the instructions for its surface finish, then season the plate according to the manual. Clean stainless steel surfaces with a damp cloth and polish with a soft, dry cloth. For discoloration, the manual specifies using a griddle cleaner. It notes that carbonized grease can impede heat transfer, contribute to uneven browning and reduce cooking efficiency. The service manual says detailed cleaning procedures are in the installation and operation manual supplied with the unit.

For an extended shutdown, the manual instructs operators to turn the griddle shutoff valve and/or main gas supply valve OFF, unplug the electrical cord if applicable, and apply a heavy coat of vegetable oil over the griddle plate to inhibit rust. The manual also says valves should be checked and lubricated periodically; consult a service agency for details.

Troubleshooting

• Heat does not come on: Check whether the pilot is lit and whether the griddle shutoff valve is ON. The manual lists a thermostat problem, low gas pressure, or a shutoff valve that is not ON as possible causes; it directs operators to call for service for thermostat or gas-pressure problems.
• Pilot will not light: Confirm the griddle shutoff valve is ON. Possible causes listed include an obstructed pilot orifice, pilot gas turned off at the pilot, a problem with the pilot safety valve or thermocouple, and low gas pressure. The manual directs operators to call for service for the listed component or pressure problems.
• Pilot will not stay lit: The manual lists an obstructed or incorrectly sized pilot orifice, air blowing out the pilot, a pilot safety valve or thermocouple problem, a thermocouple not in the flame, or low gas pressure. It also notes that air may need to be purged from the gas supply by holding the pilot safety button.
• No spark: The service manual lists an unplugged power cord, faulty igniter switch, shorted igniter electrode, faulty igniter cable or interconnecting wiring, or a failed electric igniter module.
• Spark occurs but gas does not ignite: Possible causes include a closed service gas valve, air in the gas supply, insufficient gas pressure, insufficient pilot gas flow or a faulty safety valve.
• Burners ignite but do not stay lit, or one burner has a lower flame: Check for incorrect or fluctuating gas pressure, an obstructed flue, an obstructed or misaligned gas orifice, a burner problem, external airflow, or an air-shutter adjustment issue, as applicable.
• Delayed burner ignition: The manual lists gas pressure, burner seating, alignment of burner ignition ports, pilot flash tube and pilot burner, an obstructed or misaligned orifice, burner shutter adjustment and pilot flame adjustment as possible checks.
• Excessive or low heat: Possible causes include a gas shutoff valve that is not fully open, thermostats needing calibration or malfunctioning, incorrect gas pressure, a missing or malfunctioning regulator, incorrect gas type, or an obstructed or incorrect gas orifice.
• Fat smokes excessively or food sticks, burns at the edges or has dark specks: The operation manual lists a temperature set too high as a possible cause. It also notes that moisture in food may turn into steam and that the griddle surface may require cleaning.

For service work, the service manual requires electrical disconnection and lockout/tagout procedures where specified, shutting off gas, and leak-checking disturbed gas joints with soap and water—not an open flame. It is written for trained Vulcan service technicians and is not intended for unqualified repair work.

Applications

The 936RX suits commercial line cooking where a 36-inch gas griddle can handle several items at once, such as breakfast service, burgers, sandwiches and other griddled menu items. Its three separately controlled sections can be set for different foods or stages of a service period. These are examples of kitchen uses, not additional performance specifications.