Vulcan-Hart MHB24G, VHX24G5 manual GAS Pilot Pressure Adjustment

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VHX SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS

c.Replace the orifice, pressure switch and connect the lead wires to the switch. Turn the power switch ON and adjust the pressure switch again as outlined in steps 4A and 4B. Verify the pilot gas valve is energizing.

d.If the pilot gas valve is not energizing and power is available to the pressure switch, turn the power switch OFF. Replace with a new air pressure switch and adjust the switch as outlined from step 3 thru the end of this procedure.

5.Restart the ignition sequence by "rapidly" turning the power switch OFF then back ON. A rapid switching is needed to keep the boiler from starting automatic blowdown.

A.Press the reset switch to start the ignition process.

1)Listen for gas pilot ignition to verify operation.

a.If gas pilot ignition is successful, turn the ON/OFF knob for the main gas valve back to ON.

b.Listen for main gas burner ignition to verify operation.

B.Verify the pilot and main burner both ignite in succession.

1)Restart the ignition sequence by "rapidly" turning the power switch OFF then back ON. A rapid switching is needed to keep the boiler from starting automatic blowdown.

2)Press the reset switch to start the ignition process.

C.Listen for main gas burner ignition to verify operation.

GAS PILOT PRESSURE

ADJUSTMENT

WARNING: DISCONNECT THE ELECTRICAL POWER TO THE MACHINE AT THE MAIN CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT BOX INDICATING THE CIRCUIT IS BEING SERVICED.

WARNING: SHUT OFF THE GAS BEFORE SERVICING THE UNIT.

1.Open the cabinet base door to access pilot gas valve.

2.Remove the pilot pressure plug tap from the outlet side of valve.

A.Install a hose barb adaptor and attach a gas pressure manometer.

3.Turn the gas supply and power switch ON.

A.Once the boiler fills, press the reset switch to start the ignition process.

NOTE: The reset switch can be pressed after the green ready light on the switch comes ON. This indicates the water level in the boiler is at the minimum operating level.

F24700 (October 2001)		Page 34 of 68

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Contents VHX Boiler Base Series High Efficiency GAS Steamers VHX24G ShownTable of Contents VHX Series Steamers Maintenance Cleaning Introduction InstallationGeneral Boiler Control Styles Water Supply Water Conditioning SpecificationsSystem ElectricalStandard ToolsGas Supply SpecialCooking Compartment Controls Steamer OperationCabinet Base Boiler VHX Series Steamers OperationBoiler Blowdown Steamer Shut OFF Blowdown/Drain Component FunctionVHX Series Steamers Component Function Ignition Control ModuleWater Inlet Valve manual Steam Header AssemblyWater Level Pressure Relief ValveManifold Pressure Gauge Compartment Pressure SwitchSteam Solenoid Valve Steam Supply ManifoldComponent Locations Removal and Replacement of PartsVHX Series Steamers Removal and Replacement of Parts Cabinet Base Boiler ControlsCabinet Base Boiler Controls Relay Board Water Level Controls Main or Auxiliary LlcoCooking Compartment Controls Pressure Switches Water Level Gauge AssemblyBoiler Assembly Pilot GAS Valve Main GAS Valve Boiler Fill and Cold Water Condenser Solenoid ValvesBurner Head Assembly Complete Burner AssemblyHeat Exchanger VHX Series Steamers Removal and Replacement of Parts Removal Cooking Compartment DoorsGasket Latch Assembly HandleBoiler Service Procedures and AdjustmentsClean-Out InspectionWater Level Probe Housing Blowdown Descaler Cathodic ProtectorWater Level Controls TestAuxiliary Low level Cut-Off Control High Limit CyclingFill and Cold Water Solenoid Valves Small incrementsInline Water Strainer Cleaning Boiler BLOWDOWN/DRAIN Solenoid ValvePressure Switch Adjustment Main Burner Ignition ChecksGAS Manifold Pressure Adjustment VHX Series Steamer Service Procedures and Adjustments AIR Pressure Switch Adjustment GAS Pilot Pressure Adjustment Pressure Readings Inches W.C GAS Manifold Pressure Adjustment Ignition Control Module Checks TerminalsSpark Verification Test Cooking Compartment Intake Shut-Off Valve Adjustment Steam FlowDoor Sealing Adjustment Cooking Compartment DoorsDoor Latch Adjustment VHX Series Steamer Electrical OperationElectrical Operation Low Level Cut-Off & Differential ControlAuxiliary Low Level Cut-Off Board Layout and LED Legend LED LegendInitial Conditions State a Boiler Operational Status LED IndicatorReset Engaged State C Aux Water Level Satisfied State BK51 Close Air Pressure Switch Satisfied State DK32 Close Burner ON, Boiler Heating to generate steam State EInitial Fill and Preheat Sequence of OperationNEW Style Controls Boiler HL-LEDN9, N10, N11, N12, N13 go out N14, N16, N17 go outWater Refill After Initial Fill Boiler Blowdown/drainVHX Series Steamer Electrical Operation Cooking Compartment Controls This page Intentionally Left Blank Schematics Models Built After 5/25/00 New Style Boiler ControlsVHX Series Steamer Electrical Operation Models Built Before 5/25/00 Old Style Boiler Controls Cooking Compartment Controls Wiring Diagrams VHX Series Steamer Electrical Operation Models Built Before 5/25/00 Old Style Boiler Controls VHX Series Steamer Electrical Operation Cooking Compartment Controls VHX Series Steamer Troubleshooting TroubleshootingBoiler Base Controls Symptom Possible Causes Adjustments Boiler blowdown solenoid valve clogged and not fully closing Boiler Base Procedures and Adjustments VHX Series Steamer VHX Series Steamer Condensed Spare Parts List Condensed Spare Parts ListNEW Style Controls only VHX24G, VHX24G5, MHB24G