Fault Codes/Rehlko/28Rehlko28UnclassifiedGeneralWhat This Code MeansDbl Aux Sw FaultPossible Causes•Contactor fault•Controller faultRelated Rehlko Fault Codes29302731263312343SRCSYSTEMDISABLE350X000135ABrowse all Rehlko fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for 28 on your specific Rehlko unit — cited to the OEM manual, not a forum guess.Your question about 28GET THE ANSWERFree account required — we'll bring your question with you.