Furnace Question

[BobInMN]

I know that the questions here are suppose to be tractor related. But I have a question about my furnace. I do use this furnace to warm up after I come in from outside after running my tractor so I hope it is OK to ask. It is a Coleman furnace. After it runs and the main fan shuts down there is a small motor on the front that keeps running. This motor will run forever if I let it. If I give the front of the furnance a sharp bump it shuts off. What is this small motor for? Is there some way I can fix it? Or, should I just bite the bullet and call the repairman? Last time I had him out to replace a $10 part cost me about $200. I'm not saying that repairman are paid to much, it is just that I can't afford it now because I'm unemployed.

 

[old]

Can't tell you what the small motor is but I can say it sounds like you have a relay that is sticking and the fix would be to replace it, probably a $10-40 part. Would help if you told use if its gas or electric type furnace
Hobby farm

 

[BobInMN]

Thanks Old. It is a LP gas. On the front it says Coleman Evcon Presidetial.

 

[old]

Ok small motor is probably a cool down fan which runs to cool off the inside of the furnace after then burner kicks off. Either way when you hit it you knock the relay loose so it then shuts off and then when it kicks back on your back to a sticking relay so you then have to kick it to turn it off

 

[Bob]

Colemans are good for having a wiring diagram stuck to an access door. Take a look at that, and see if there's a relay that powers up the draft inducer. Likely, it is that relay that is sticking.

 

[Gary from Muleshoe]

BobInMN
Do you a have a book for this unit? The book should have a trouble code list on it or this may also be on the panel. See if while the fan is running if you have a red light flashing. If you do count the number of flashes. Then refer to the code list. This should pin point the problem.

 

[old]

Also as Bob says most furnaces will have a diagram for the wiring inside. BE SURE TO TURN off the power. Pull the front cover off and then look for the diagram. If you don't see it. Then look for the electric control panel and pull that cover and it should have the diagram on the inside of that cover. BTDT and have fixed a good many furnace problems my self in the past.
Hobby farm

 

[WantACaseLASomeday]

http://www.furnacesite.com/s/coleman_evcon_furnace

 

[Anonymous-0]

Is this an old one or newer high effeincy one?

 

[BobInMN]

Thanks for all the replys. I took the front cover off yesterday. There is a small round aluminum box close by the motor with a lot of wires running in and out of it. I am assuming that this may be the relay switch? Just for the heck of it I flicked it with may finger a few times. Guess what? When the furnance shuts down the motor runs for a while then shuts down like it is suppose to. Maybe that is all it needed. Wish me luck.

 

[KEB1]

Small fan is most likely a forced draft for the burner. Should run on a control relay, sounds like you've got a sticky one. Not sure if theres a thermal switch on a forced draft or not, would have to go dig out a wiring diagram.

Banging on it to unstick the relay will help for a while, but if the contacts are pitted enough to stick closed you're eventually going to need to replace it. If it's an open frame relay you can polish the contact points with a point file or some emery cloth (NOT sandpaper). If it's a sealed relay you're SOL. Just be sure to turn the power off first, as that relay probably switches 120 volts for the blower motor.

Keith