A. O. Smith heat pump water heater error codes

Pick your series. Codes differ between generations, so match the model number on the rating label. Also sold as State, American, Lochinvar, Reliance.

• Voltex AL Smart / Signature 900 Standard (HPTS, HPS10)24 codes · Control Assembly with LCD display, alert icon/indicator, red LED and beeper; 3-digit error codes
• Voltex MAX / Signature 900 Premium (HPTA, HPA10)26 codes · Control Assembly with LCD display, alert indicator, red LED and beeper; 3-digit error codes; Guest Mode and Hot Water+ Mode
• Voltex 120V plug-in (HPTV, HPV10)26 codes · Control Assembly with LCD display, alert indicator, red LED and beeper; 3-digit error codes
• Voltex hybrid with letter codes (HPTU, 2016–2019)21 codes · User Interface Module (UIM) LED segment display with Mode/Enter and up/down buttons; letter/number codes; possible audible alarm
• Early Voltex hybrid (FPTU, 2015 manual)20 codes · User Interface Module (UIM) display; letter/number codes