Raypak WH 0135A Installation & Operating Instructions Manual

Also see for Econopak WH-0090: Installation and operating instructions

16SERVICINGPROCEDURESGeneral Location of ControlsSequence of OperationIntermittent Ignition Device (IID)Heaters equipped with the IID system will automatical-ly light the pilot burner first and then the main burner,each time there is a call for heat from the tankstat.Whenever the tankstat calling for heat, the circulatorsupplied with the heater, will be energized and shouldbe running.The ignition control module will also be energized toinitiate the pilot ignition by opening the first main valve(pilot). At the same time, the electronic spark genera-tor in the module produces a high voltage spark pulseoutput that lights the pilot burner. If the pilot burnerdoes not light, the module will not energize the secondmain valve and the burners will not light. Ignition sparkcontinues only until the timed trial for ignition periodends.Then, the module goes into safety shutdown or lock-out. Lockout de-energizes the first main valve operatorand closes the first main (pilot) valve in the gas con-trol, stopping pilot gas flow. The ignition control systemmust be reset by setting the tankstat below water tem-perature for one minute or by turning off power to themodule for one minute.When the pilot flame is established, flame rectificationcircuit is completed between the sensor and burnerground. The flame sensing circuit in the moduledetects the flame current, shuts off the spark genera-tor and energizes the second main valve operatorwhich opens the second main valve. This allows gas toflow to the burners where it is ignited by the pilot burn-er flame.When the tankstat is satisfied, the valve operators arede-energized shutting off the pilot and main burners,and also the circulator.Start-up ProceduresFilling the SystemFill system with water. Purge all air from the systemusing purge valve sequence. After system is purged ofair, lower system pressure. Flush system before put-ting into operation to ensure that foreign material doesnot damage pump seals.Checking the CirculatorBefore lighting the heater and after system is filled,make sure that circulator is operating properly. Manualgas valve should be off.NOTE: Circulator motor supplied with the heaterdoes not require lubrication.Ignition Module(Auto Ignition Only)Fig.# 8195.3CirculatorManual Reset Limit(in heater behind panel)PressureRelief ValveField WiringCompartmentTemperature SensorIgnition Module(Auto Ignition Only)TransformerRoll-Out SensorGas ValveFig. 8: General Location of Controls