My fan will not shut off it just keeps running i have a trane relay if so where is it at whats it look like?

Question

i have a trane heating and air conditioning my fan keeps running and will not shut off is it a relay if so where is it and what does it look like for i can replace it

Answer 1

Gas or electric heat, it makes a big difference.

If gas, you most likely need a new control board, if electric the relay is in a small metal box inside the air handler near the thermostat wire connections. This is not a standard relay, it has a time delay built into it. These things are a PIA to change due to limited working room. There is no second chance with these, wire it wrong, buy another one.

Answer 2

I know this may sound silly, but have you checked the thermostat to make sure the fan has not been changed from "auto" to "on"?

If that's not the problem, there should be a  switch where the power goes into your heat exchanger (which contains the fan.) Turn it off and wait a few minutes and turn it back on.

If it comes back on, there is more than likely a problem with the thermostat or the relay switch to the fan.

If it's  the latter, it is a little too complicated to explain here, and would need a repair call unless you are good with electrical repairs.

Answer 3

These days it is most likely on the furnace control board and essentially not replaceable, means a new board.

Generally, on the furnace cover or the blower door is a schematic and often on those will also be a layout of the controls of the furnace. Sometimes it is marked on the board itself.

If separate, it will tell you where the relay is located or least what color wiring goes to it so you can maybe trace it to identify.  

On some models the fan runs all the time if you lose the 24volts from a safety opening or other failure. You didn't say if everything was working normally otherwise.  

Good Luck.

Ps, you might try tapping lightly on the relays to free it up. They will be the little square or rectangular "boxes" mounted on the board. But still will need replacing. They generally stick because they are slightly burnt and fused the contacts.

Answer 4

Move your fan lever from ON to AUTO on your thermostat.

Answer 5

Hi Brant.............I'm just going to take a guess...........usually electrians put them in closets or out of the way ceiling or wall area's where eyes donot catch the sight of them.  The one's that I have worked on, are about 11/2" square. all the best.