Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Temp drops to 55 at night

lab
lab Member Posts: 3

although my forced air gas furnace keeps the temp I set, 68°, 24/7, it drops to 55° at night. The furnace feels warm, so I thought maybe the fan wasn’t working. I set the thermostat to the fan staying on and it worked, but the temp didn’t go up.
Can anyone help?

Comments

  • hot_rod
    hot_rod Member Posts: 23,412

    filters clean? Did it work years past?
    Keep the thermostat in the heat mode.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • lab
    lab Member Posts: 3

    yes it worked in the past and until a couple nights ago. Blower fuse was replaced about 6 months ago; Other than that, no issues. Thermostat is in heat mode -

  • Jamie Hall
    Jamie Hall Member Posts: 24,878

    Do you have a setback on the thermostat?

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • worldclasshvac
    worldclasshvac Member Posts: 25

    Ita likely tripping a limit and shutting down prematurely. Very common issue and the fix depends on what furnace is there. Post the model #. Could also be weak inducer causing pressure switch to flutter

  • lab
    lab Member Posts: 3

    thank you all. I had a friend check it because it quit completely, and it’s a relay. Won’t be here til Monday, but it’s a $4.50 part.

    PC7060