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Honeywell L7224 - Err 1 comes back after new sensor

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Superlim9
Superlim9 Member Posts: 4
Hello All,

I woke up to a bit of a chilly house this morning. Inspection of the furnace yielded an err code "1" on the aquastat screen. I replaced the sensor and the furnace will start run for 5 sec and then the error comes back. can unplug the sensor and then plug it back in and 5 sec run again.

Just curious if I need to replace the entire unit.

Comments

  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
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    Maybe it's the plug in the aquastat itself. I assume the sensor is all the way in the well, making good contact.

    There was an error rendering this rich post.

  • Superlim9
    Superlim9 Member Posts: 4
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    yeah you are correct all the way in and tight fitting. no corrosion in the well
  • HVACNUT
    HVACNUT Member Posts: 5,865
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    You had an extra sensor just lying around?
    STEVEusaPA
  • Superlim9
    Superlim9 Member Posts: 4
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    I have a FW Webb store next town over so I went and grabbed one
  • HVACNUT
    HVACNUT Member Posts: 5,865
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    I've never had to replace the sensor on that aquastat. But since you replaced it and it's still showing E1, I'd assume the aquastat is bad.

    On a last ditch effort, I would remove and check/clean the outer well surface.
  • Superlim9
    Superlim9 Member Posts: 4
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    its a head scratcher... left the power off for 2 hrs while i was figuring stuff out and checking stuff. Turned it back on and went through the settings... and it started working... ordering a spare aquastat to have on hand now.. just in case
    JohnGorno
  • HVACNUT
    HVACNUT Member Posts: 5,865
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    Looks like the Gremlins aren't in quarantine. 😈
    JohnGorno
  • JohnGorno
    JohnGorno Member Posts: 1
    edited October 2022
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    Just replying to the first "Honeywell Aquastat Err 1" thread that Google found... I only later noticed the helpful error code list inside the cover panel -- "Err 1 = sensor error."
    My plumber caught a cardboard gremlin! "Err 1" (which -- he simply removed a 2"x1" cardboard installation guide(?) (which says, "Set thermostat anticipator to 0.1 amps") which must have been plugged into the circuit board at the factory and left there without noticeable effect until recently, thus banishing persistent "Err 1" -- aquastat stays on again! The aquastat is at least 8 years old, furnace has been a bit temperamental at the beginning of the last two heating seasons: I thought it was a squirrelly wall thermostat, furnace guy thought it was wiring gone bad inside the aquastat (correct... in the most general sense). I imagine the cardboard introduced or exaggerated some stray static voltage on the circuit board -- weirder things have happened -- may be a warning of near-term failure, but, after both service calls, I'm $500 wiser now. :neutral:
    It crapped out again, and I fiddled with the sensor wires, works now. :shrug: