Minnesota Electric strip heat not working

Discussion in 'Maintenance and Troubleshooting' started by StirlingSilver, Jan 15, 2024.

  1. StirlingSilver

    StirlingSilver New Member

    Unit: Waterfurnace Series 7 (8 years old), 048, 6 zones, Intellizone 2, Airboss zoning system

    I needed to have my air coil replaced in November due to a refrigerant leak. An aluminum coil was installed. Fast forward to last week, I started receiving FP2 freeze protect, E4 errors. I checked pressures in the loop lines which were normal. Incoming water temp was 44°, outgoing 41. Using my AID tool I cleared the error and restarted the furnace. It was fine for several days then the error came back. Clearing the error and resetting the circuit breakers would now work only momentarily before the error came back on (this past weekend). I put the main stat in E heat mode but noticed shortly thereafter that only cool air was coming out of the vents. Outgoing air from AID tool showed 65°. Moreover, power usage under Aux was zero, the strip heat was not working. I could not get the electric heat to come on whatsoever. The temperature was dropping fast outside, now near 10°.
    I set the main stat back to heating mode, cleared the error, reset the breakers on the auxiliary heater inside the unit, as well as reset the breakers at the panel. This time, the geo came back on and the FP2 error has not returned. (FP2 sensor has been ordered and is shipping). Last night, all stats were calling but the system went into standby mode indefinitely until I reset it again at the breaker. Electric heat is still not coming on though the system says it is.
    Any advice would be greatly appreciated, specifically with regards to troubleshooting the electric heat side.
     
    Last edited: Jan 15, 2024
  2. mrpac

    mrpac Member

    Is there a chance that the main feeding breaker for the aux heat is tripped, or turned off? I purposely turn my aux breaker off when I don’t want the system consuming lots of energy unknowingly. It is generally a separate electrical feed.

    You mentioned that your tool indicated no energy usage, even though the system was not running properly - I would have thought a WF7 would have been sophisticated enough to know if AUX heat was working.
     
  3. StirlingSilver

    StirlingSilver New Member

    No breakers are tripped. AID tool showed emergency heat mode (as set on main stat) and blower was on but Aux power consumption was zero.
     
  4. mrpac

    mrpac Member

    It sounds like you need to test your aux heat independently. If the heat pump itself is not functioning, is it possible to test the call to aux heat? There may be an option to turn on the aux heat, if not turn the setpoint up 3 deg and it will most likely turn on.
    The other possibility is that the 220v feeding the heater circuit may be open somehow. Again, this is typically wired from separate circuits.
    Hope this helps, its still cold out there
     
  5. StirlingSilver

    StirlingSilver New Member

    I'll be testing the Aux board this weekend to check voltage, then the Aurora board if Aux board checks out. Geo is running ok but I'll put master stat on E heat to confirm aux should be running.
     
    Last edited: Jan 20, 2024

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