Gas forced air furnace cycles off and on during warm up

During warm up, our new furnace (Toll Bros.) comes on and off several times before hitting the set temperature on the thermostat. Why?

  4 answers
  • It shouldn't call them back while you are still under warranty.

  • Kauai Breeze Kauai Breeze on Dec 01, 2017
    Sounds like the flame isn't adjusted correctly or the blower isn't staying on. Call the contractor ASAP, they need to make it right!

  • Dianacirce70 Dianacirce70 on Dec 01, 2017
    Does it cycle off and on often while its running? That could be a variety of problems, and all of them require having it looked at. It could be the heat exchanger is getting wear and could crack, causing a carbon monoxide issue, could be something as simple as a thermostat failing. No matter what, have it looked at.

  • Chris Moose Chris Moose on Dec 01, 2017
    It's a new furnace (6 months old) so I don't think it's a crack. Your recommendation to install a CO detector is accepted. It's either the thermostat or too much heat pooling near it caused waves of heat to come and go.