64659-001 REV. A 07/06/1824SymptomLights PossibleCorrectionsFlash T-Input Valve Blower 24V/CalAppliance runs, oventemperature at ornear t-stat set point,slowly increasesabove set point overtimeFlash On On On On1. Verify proper gas orifice size fordesired firing rate and type of gas.2. Check low pressure setting ofmodulating gas valve; adjust asnecessary.Appliance runs,temperature at t-stat set point slowlydecreases whenappliance is loadedFlash On On On On1. Verify proper gas orifice size fordesired firing rate and type of gas.2. Check high pressure setting ofmodulating gas valve; adjust asnecessary.Appliance runs,temperature cyclingabove and below t-stat set point byapproximately +/-5oFFlash OnOnorFlashOn On1. This is normal operation foriHEAT control with V53 and latersoftware. A flashing Valve lightindicates the burner has beenturned off to maintain appliancetemperature.2. Verify proper dip-switchposition for appliance and gastype.3. Check low pressure setting ofmanual gas valve; adjust asnecessary.Appliance runs andiHEAT system isrunningFlash Off Flash On FlashSystem is in low gas pressurecalibration mode. Refer toModulating Valve section.SERVICE INFORMATION