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Furnace Won’t Turn On Automatically

Taj Member Posts: 1
edited June 2021 in Gas Heating
Hi, I have been having this issue over this past winter and I really want to get this resolved before this coming winter. Our Honeywell Aquastat relay transformer blew and we changed the entire unit and everything seemed fine, then it went out again! 

We had warranty on that new unit so we replaced it once more but this time the furnace only turned on if I tucked something in between the clapper which kept the heating going. But I don’t want to keep doing this as it may seem unsafe, I want my thermostat to go back to being able to turn the furnace on without me having to play with the clapper (circulating relay switch). Any suggestions or help? 

Guys around my area are charging $ (almost the price of a new aquastat relay) just to come out to diagnose the issue. All help and suggestions will be appreciated. 


    EBEBRATT-Ed Member Posts: 13,750
    Post the model of the aquastat and some pictures.

    Don't keep pushing in the clapper, your bypassing some safety controls and could have a problem.

    Your probably going to need a multimeter to check this out.

    If your not comfortable with electrical call a pro
  • mattmia2
    mattmia2 Member Posts: 8,364
    In fact I would argue that it is very likely there was never a problem with the control but that one of the safety controls was open.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 6,019
    edited June 2021
    @Taj Can you take a picture of the control with the cover off so we can see what is inside. the part number will also help. If you are manually pushing (pulling) the clapper on a relay you may be bypassing more than just the thermostat. there may be safety devices that also operate that relay. if you bypass a safety device like a flame proving signal, you may be operating in a dangerous condition.

    More info needed and soon! Stop manually operating the relay.

    Pictures of the entire heater will also be helpful.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics