Is there something wrong with my furnace, my thermostat, or something else?

I have a propane gas furnace. I was away for a few weeks and left the furnace on 52 degrees. When I returned home, the house was freezing with no heat. I could tell that at some point the electricity had gone off, but it was on when I came in, but the furnace wasn't on. (My fridge also seemed to have stopped working - frozen foods all melted). The thermostat was all the way down. The furnace room in a separate area from thermostat was warmish.  I turned off and on the thermostat and heard it click on and got a bit of heat. I had to keep turning off and on a number of times for heat to continue. Finally the heat stayed on and it took a number of hours for house to warm back up. Now (next day) it seems to be working normally.  My fridge also, I pulled out the plug and put it back in. At first didn't work but then started working again.  So I'm wondering what is or was wrong. Usually if electric goes off, when it comes back on the furnace will also come back on. It's kind of strange. Does anyone have an idea what might have happened? Am concerned, as I do go away off and on in the winter.  thanks for any help!

4 Answers

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  • Anonymous
    1 month ago

    The computers had to "wake up" after the power loss.  The cold did not help it.  Took some time. Voltage could have been low after power came back.  I would not worry about anything.  Nothing is broken, nothing to be fixed. 

    Set your stat to 65 when you are away.  50 is too cold for the house.

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  • 1 month ago

    If there's power, the furnace should fire up if the stat is good and calls for heat, irregardless if the power went off before for any length of time.

    You having to turn the stat on & off to get action, makes me think there's a tired relay in the circuit board causing the issue. It could be something else, like a loose wire or a limit switch, but if a relay is going out, the problem may go away for a bit, but will resurface later.

    On one of your furnace service doors, is a sequence protocol list. This will run your furnace through most of its functions (induction blower, main blower, ignition system) to see if it's working properly. The burners will not ignite with this procedure . You can do this yourself if you're a bit handy.

    Also, there should be an LED light on your circuit board and should be visible through a small window on one of the service panels. The legend of any blinking lights should be on the furnace service door too.

    If your house got below freezing for any length of time, and your fridge has a digital thermostat and/or an electronic defrost control, most will turn themselves off and not turn back on, even when the room temperature returns to normal. Not all, but most.

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  • 1 month ago

    ask neighbors how long the power was out. also ask them if they had similar issues or noticed anything unusual when power returned.

    idea: electric circuits can store energy in capacitors. the furnace certainly has at least one -- the run/start capacitor for the blower motor. if power is off for a fairish length of time [hours or more] the stored energy in the capacitors may have leaked out and then been unable to restart the furnace after the power came back on. [when the blower motor for a gas furnace fails to start, an interlock circuit shuts the furnace down -- this prevents overheating and a possible fire.]

    Source(s): grampa
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  • Pearl
    Lv 7
    1 month ago

    maybe you should pay someone to come in and check it

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