Furnace experts

[ARB1977]

Originally Posted By: Tdbo
Originally Posted By: Nukeman7
Sounds like your thermostat is defective.


Definite possibility.

When I pulled the fan wire going into the thermostat the fan didn't turn off. It's up stream somewhere.

 

[Leo99]

Originally Posted By: ARB1977
Originally Posted By: Leo99
Originally Posted By: ARB1977
I did disconnect the green wire behind the thermostat while the fan was running. That did nothing. I'm almost tempted to open up the aircycler controller and remove the green wire to the fan. If the fan shuts off, that might be the issue.


Simplifying the system will help you troubleshoot.

Lol. I didn't know much at all about the system. Till this happened.


I woke up a cold house last week. Spent an hour reading and watching youtube videos educating myself as to how forced hot air furnaces work. Opened my furnace to inspect it and as soon as the door was off, the furnace kicked on. I cleaned the flame sensor. It's been working fine since. No idea what was wrong.

I'm guessing you might have something analogous to a 3-way switch for your fan. Either the thermostat or that aircycler thing can turn the fan on.

If the fan comes on without the thermostat calling for heat, I'd say it's not the thermostat. it's either the control board on the furnace or it's the aircycler that is not working properly.

 

[Tdbo]

Originally Posted By: ARB1977
Originally Posted By: Tdbo
Originally Posted By: Nukeman7
Sounds like your thermostat is defective.


Definite possibility.

When I pulled the fan wire going into the thermostat the fan didn't turn off. It's up stream somewhere.



Sounds like either the relay or a board in the unit.
In my case when the thermostat went, both the A/C compressor and the furnace were running at the same time (in December with 20 degree temps.)
Best of luck.

 

[KrisZ]

Originally Posted By: ARB1977

I realized there's a aircycler control on top of the furnace. It almost looks like a second thermostat. From there it goes into the circuit board. For awhile now the display has gone out in the aircycler controller. So I'm not sure if that's it or not.


What do you mean "aircycler control"? Is it by any chance a humidifier with a separate controller? If that is the case, then they are programmed to turn on the air handler fan to regulate the humidity level, and it will operate separate from the furnace.

 

[ARB1977]

Originally Posted By: KrisZ
Originally Posted By: ARB1977

I realized there's a aircycler control on top of the furnace. It almost looks like a second thermostat. From there it goes into the circuit board. For awhile now the display has gone out in the aircycler controller. So I'm not sure if that's it or not.


What do you mean "aircycler control"? Is it by any chance a humidifier with a separate controller? If that is the case, then they are programmed to turn on the air handler fan to regulate the humidity level, and it will operate separate from the furnace.

There isn't a separate fan. It seems the aircycler controller is wired from the thermostat then goes to the circuit board. Both will turn the fan on or off.

 

[ARB1977]

Originally Posted By: Tdbo
Originally Posted By: ARB1977
Originally Posted By: Tdbo
Originally Posted By: Nukeman7
Sounds like your thermostat is defective.


Definite possibility.

When I pulled the fan wire going into the thermostat the fan didn't turn off. It's up stream somewhere.

The crazy thing is now it's working as it should. Once the heater kicked on and did it's thing. Everything had shut off. Even the fan at some point came on its own and shut off. So who knows.

Sounds like either the relay or a board in the unit.
In my case when the thermostat went, both the A/C compressor and the furnace were running at the same time (in December with 20 degree temps.)
Best of luck.

 

[ARB1977]

Here's a pic for aircycler controller.

 

[ARB1977]

Here's a pic of the fan and circuit board.

 

[ARB1977]

Here's a pic of the thermostat.

 

[EA82]

At the bottom on the furnace picture, try to disconnect all the control low voltage wires, just take a picture if you don't remember where they go, and see if the fan still runs.
They didn't even put a plenum on that furnace, they connected flex duct straight to it.

 

[Leo99]

post picture of the front of the aircycle controller. What triggers that to turn the fan off/on?

 

[ARB1977]

Originally Posted By: Leo99
post picture of the front of the aircycle controller. What triggers that to turn the fan off/on?

Very simular to this one. Although my display went out a few years ago. It's wired from the thermostat then goes into the circuit board.