Water heater & furnace error codes
Every chart here is transcribed from the manufacturer’s own manuals, not copied from other websites, many of which get the codes wrong. Pick your brand:
Water heaters
Rheem Gas Water Heater Status Light Codes
Rheem residential gas tank water heaters with a thermopile-powered gas control and status lightBradford White Water Heater Status Light Codes
Bradford White Defender FVIR residential gas models such as RG230T, RG240T, RG250T/S/H/L, RG130T, RG140T, RG150T and LG255HA.O. Smith Gas Water Heater Status Light Codes
A.O. Smith GCV, GCVH, GVR, GCVL, GVRL, GCVT, XCV, XVR, XCVL, XGV, XVRL, XCVT and Series 300/301 gas models with a Honeywell/Resideo WV8840-type controlNavien Tankless Water Heater Error Codes (NPE-2)
Navien NPE-2 condensing tankless water heaters: NPE-180, NPE-210 and NPE-240Rinnai Tankless Water Heater Error Codes
Rinnai SENSEI N-Series condensing unitsRheem Tankless Water Heater Error Codes
Rheem RTGH condensing and RTG non-condensing gas tankless water heaters
Rheem residential gas tank water heaters with a thermopile-powered gas control and status lightBradford White Water Heater Status Light Codes
Bradford White Defender FVIR residential gas models such as RG230T, RG240T, RG250T/S/H/L, RG130T, RG140T, RG150T and LG255HA.O. Smith Gas Water Heater Status Light Codes
A.O. Smith GCV, GCVH, GVR, GCVL, GVRL, GCVT, XCV, XVR, XCVL, XGV, XVRL, XCVT and Series 300/301 gas models with a Honeywell/Resideo WV8840-type controlNavien Tankless Water Heater Error Codes (NPE-2)
Navien NPE-2 condensing tankless water heaters: NPE-180, NPE-210 and NPE-240Rinnai Tankless Water Heater Error Codes
Rinnai SENSEI N-Series condensing unitsRheem Tankless Water Heater Error Codes
Rheem RTGH condensing and RTG non-condensing gas tankless water heaters
Furnaces
Carrier Furnace Blinking Light (Status) Codes
Carrier 58CVA/58CVX variable-speed two-stage gas furnacesGoodman Furnace Flash Codes (LED Blinks)
Goodman/Amana single-stage furnaces with LED boards, such as GMES80, GCES80 and GMSS92Trane & American Standard Furnace Error Codes
Trane and American Standard *UH1 / *DH1 condensing gas furnaces with LED codesLennox Furnace Error Codes
Lennox EL296UHV and SL280UHV furnaces with ignition control 103130
Carrier 58CVA/58CVX variable-speed two-stage gas furnacesGoodman Furnace Flash Codes (LED Blinks)
Goodman/Amana single-stage furnaces with LED boards, such as GMES80, GCES80 and GMSS92Trane & American Standard Furnace Error Codes
Trane and American Standard *UH1 / *DH1 condensing gas furnaces with LED codesLennox Furnace Error Codes
Lennox EL296UHV and SL280UHV furnaces with ignition control 103130
Codes differ between control boards and model years. If your unit has a code chart on its label or door, that chart wins.