Furnace cycle abnormal

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Furnace cycle abnormal

Postby angie291 » Wed Mar 15, 2017 6:27 pm

I just got a new blower motor installed and it took all evening to warm the place back up, as it was off for a day, and didn't shut off. I had to turn the thermostat to get it to shut off and go into a regular cycle, which took a few tries. Heat is always coming out but it got colder overnight and in the morning. I put in a new air filter and that improved some but not what I thought it should. After I put the filter in, the cycle changed, the blower turns on a heat blows for a minute, turns off for 30 seconds, then turns back on and resumes regular cycle. It also seems like it should stay on a little longer, but thermostat is up to temperature so really it should shut off. Overall, it is just running different that before I had the motor replaced. I called the guy who put it in and he didn't think there's anything wrong. I think he just didn't want to help. So now I'm stuck figuring this out myself. What could cause this new cycle change?
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- Furnace cycle abnormal

Postby Freon » Thu Mar 16, 2017 10:10 am

You said, "After I put the filter in, the cycle changed, the blower turns on a heat blows for a minute, turns off for 30 seconds, then turns back on and resumes regular cycle. " Would you please clarify a few things. When you say, "the blower turns on a heat blows for a minute, turns off for 30 seconds, then turns back on.." is only the blower turning off and back on or is it the furnace flame that is turning off and then back on while the blower continues to run?

It is possible the new blower motor is a little different from the old one. That could explain a slight change in furnace operation. My question above concerns the possibility the main burner is going on and off while the blower remains on circulating air. That could indicate not enough airflow through the furnace heat exchanger although the new filter should have helped airflow.

From a subjective perspective, does the flow of air from the supply registers (air into the rooms) "feel" about as strong as it was with the old motor?
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