Vulcan-Hart MHB24G, VHX24G5 manual Adjustments

Page 63

VHX SERIES STEAMER - TROUBLESHOOTING

SYMPTOM		POSSIBLE CAUSES

Gas odor.	1.	Leaks in pipe fitting connections or components.
	2.	Leaking pressure tap plug on pilot or main gas valve; loose or
		missing pressure adjustment screw cap on main gas valve.
	3.	Leaking gaskets in air/gas mixture path.
	4.	Pilot or main gas valve malfunction (improper venting or vent
		blocked).
	5.	Incorrect gas pressure.
	6.	Malfunctioning gas burner.
	7.	Blocked or dirty air orifice on blower.
	8.	Blocked or dirty gas orifice.
	9.	Malfunctioning blower.
	10.	No pilot ignition.
	11.	Improper hood venting, vent blocked or room not vented
		properly.

Drain box leaking.	1.	Clog in drain line plumbing.
	2.	Drain restricted to size below 1-1/4" pipe.
	3.	Drain extension plumbing not at the proper slope or plumbing
		too lengthy.
	4.	Grommets not sealing.
	5.	Steamer draining while under pressure and relief valve opening
		at the same time (flooding drain box).
	6.	Cold water condensing spray is "over spraying".
	7.	Drain box thermostat improperly set or malfunctioning.

Cold water condenser not operating	1.	Water supply valves(s) turned off.
properly.	2.	Cold water condenser solenoid not receiving power, inoperative
		or valve plugged.
	3.	Cold water condenser thermostat malfunction or needs
		adjustment.
	4.	Plugged spray nozzle.
	5.	Water supply pressure high (improper valve operation).

Heat coming on without water in boiler	1.	Lime scale build-up on water level probes (shorted to ground).
(Dry firing).	2.	Retention of water in probe housing (assembly or aux.LLCO).
	3.	Water level control malfunction.
	4.	Aux. water level control malfunction.

Spark Ignitor not sparking.	1.	Ignitor boot on ignition cable loose, damaged or missing
		causing excessive ignition voltage leakage.
	2.	Loose, broken or damaged lead wires (including ground) from
		ignition module to ignitor.
	3.	Poor ground on ignitor assembly.
		NOTE: Items 4, 5 & 7 see "IGNITION CONTROL MODULE
		CHECKS" in "SERVICE PROCEDURES AND
		ADJUSTMENTS".
	4.	Ignition module not receiving power.
	5.	Ignition module malfunction (no output voltages or spark).
	6.	Ceramic flame rod insulator on ignitor cracked or damaged
		from extreme heat.
	7.	Incorrect spark gap setting.

Page 63 of 68		F24700 (October 2001)

Image 63

Contents VHX24G Shown VHX Boiler Base Series High Efficiency GAS SteamersTable of Contents VHX Series Steamers Installation Maintenance Cleaning IntroductionGeneral Boiler Control Styles Electrical Water Conditioning SpecificationsSystem Water SupplySpecial ToolsGas Supply StandardVHX Series Steamers Operation Steamer OperationCabinet Base Boiler Cooking Compartment ControlsBoiler Blowdown Steamer Shut OFF Ignition Control Module Component FunctionVHX Series Steamers Component Function Blowdown/DrainPressure Relief Valve Steam Header AssemblyWater Level Water Inlet Valve manualSteam Supply Manifold Compartment Pressure SwitchSteam Solenoid Valve Manifold Pressure GaugeCabinet Base Boiler Controls Removal and Replacement of PartsVHX Series Steamers Removal and Replacement of Parts Component LocationsCabinet Base Boiler Controls Water Level Controls Main or Auxiliary Llco Relay BoardCooking Compartment Controls Water Level Gauge Assembly Pressure SwitchesBoiler Assembly Boiler Fill and Cold Water Condenser Solenoid Valves Pilot GAS Valve Main GAS ValveComplete Burner Assembly Burner Head AssemblyHeat Exchanger VHX Series Steamers Removal and Replacement of Parts Cooking Compartment Doors RemovalGasket Handle Latch AssemblyInspection Service Procedures and AdjustmentsClean-Out BoilerDescaler Cathodic Protector Water Level Probe Housing BlowdownTest Water Level ControlsAuxiliary Low level Cut-Off Control Cycling High LimitSmall increments Fill and Cold Water Solenoid ValvesBoiler BLOWDOWN/DRAIN Solenoid Valve Inline Water Strainer CleaningMain Burner Ignition Checks Pressure Switch AdjustmentGAS 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 Terminals Ignition Control Module ChecksSpark Verification Test Cooking Compartment Doors Intake Shut-Off Valve Adjustment Steam FlowDoor Sealing Adjustment Cooking CompartmentVHX Series Steamer Electrical Operation Door Latch AdjustmentLow Level Cut-Off & Differential Control Electrical OperationAuxiliary Low Level Cut-Off LED Legend Board Layout and LED LegendAux Water Level Satisfied State B Boiler Operational Status LED IndicatorReset Engaged State C Initial Conditions State aBurner ON, Boiler Heating to generate steam State E Air Pressure Switch Satisfied State DK32 Close K51 CloseHL-LED Sequence of OperationNEW Style Controls Boiler Initial Fill and PreheatN14, N16, N17 go out N9, N10, N11, N12, N13 go outBoiler Blowdown/drain Water Refill After Initial FillVHX Series Steamer Electrical Operation Cooking Compartment Controls This page Intentionally Left Blank Models Built After 5/25/00 New Style Boiler Controls SchematicsVHX 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 Troubleshooting VHX Series Steamer TroubleshootingBoiler Base Controls Symptom Possible Causes Adjustments Boiler blowdown solenoid valve clogged and not fully closing Boiler Base Procedures and Adjustments VHX Series Steamer Condensed Spare Parts List VHX Series Steamer Condensed Spare Parts ListNEW Style Controls only VHX24G, VHX24G5, MHB24G