Originally Posted by hvacservicetech_07
Thanks again for the suggestions!
There is a small square post sticking up between the 2 vertical tabs on that switch (this is what I was touching when jumping the furnace).
I pressed down on that post and did here a faint click sound, but couldn't really tell if anything physically moved.
Then I tested the furnace... here's what I observed
Thermostat was on the off setting. Room temp was below what the thermostat setting was.
I turned the power back on to the furnace.
Blower didn't turn on.
My wife turned the thermostat to heat, while I watched the furnace.
Once the thermostat was switched to Heat, blower turned on.
A few seconds after that, the burners ignited.
The furnace stayed on until reaching the set temp.
Burners turned off, and blower kept going.
Blower continued to run and did not turn off.
Room temp dropped below set thermostat temp.
Burners did not ignite. Blower kept going.
I then did the same test and before starting pinched down on that post again. Heard the same faint click.
The furnace did the same behavior... started as it should normally do, shut off heat when it should, and blower kept blowing. Same behavior as above.
Doing the test, it seems like the furnace works properly until it gets to the end of the cycle. The blower keeps blowing, but the burners never re-ignight when they should.
Could that still be an indicator of a bad rollout switch (i.e. the furnace will go through a cycle and not come back on while leaving the blower running)?
And can that cause a blower to not shut off?
Interesting stuff for sure!