Fault Codes/Discovery Energy, LLC (Rehlko)/D04Discovery Energy, LLC (Rehlko)D04UnclassifiedElectricalWhat This Code MeansField overvoltageRelated Discovery Energy, LLC (Rehlko) Fault CodesOVER VOLTAGEP0131D01P0132P0561P0562P0652P0698P0699UNDER VOLTAGED09D11Browse all Discovery Energy, LLC (Rehlko) fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for D04 on your specific Discovery Energy, LLC (Rehlko) unit — cited to the OEM manual, not a forum guess.Your question about D04GET THE ANSWERFree account required — we'll bring your question with you.