Mobile Home Furnace Problem

colu41 · 10-02-2011, 12:38 PM

I have a mobile home with an electric furnace. Now I have a fan switch that is bad. BUT, when I hardwire the wires together, the fan obviously turns on, but blows cold air. Is there another problem? Or will the fan switch fix this also?

The fan switch when bad last year also. Had a tech come in to diagnos but, found nothing but the fan switch. Any help would be greatly appreciated.

**beenthere** · 10-02-2011, 05:30 PM

Could be a heat sequencer is bad.

colu41 · 10-02-2011, 06:46 PM

Where would that be located?

Master of Cold · 10-02-2011, 08:51 PM

What is this fan switch that is bad?
Is it the fan relay, or the thermostat?

REP · 10-02-2011, 08:58 PM

There has to be a relay,contactor,sequencer ,something that puts line voltage to the heating elements and or fan.
This usually has a low voltage coil that the stat energizes on a call for heat.

Tator1076 · 10-02-2011, 09:06 PM

sequencer sound to be that problem or limit. also need to find what took it them out. I can be dirty filter or even plugged coil if has a/c.

colu41 · 10-02-2011, 09:56 PM

It does have AC.

and this is the part thats bad

well, thats what I noticed first. Didn't check the switch next to it

Master of Cold · 10-02-2011, 10:03 PM

That's a thermal fuse.

colu41 · 10-02-2011, 10:04 PM

Quote:

Originally Posted by Master of Cold

That's a thermal fuse.

So, this when this switch is plugged in, the fan does not turn on at all. When I hardwire the 2 wires together, the fan pops on, but blows cold air. What does this switch do>?

REP · 10-02-2011, 11:16 PM

That is not a fuse,its a switch.It is normally open,when it senses 110 degrees it makes the circut,when it then senses 90 degrees it opens again.
There very well could be a fuse in line with the heating elements that would have opened if the fan didn't come on to cool the plenum.
You really need a meter to check electrical systems out.

Master of Cold · 10-03-2011, 08:25 AM

Can you take a picture of the actual switch, and the wiring in the unit..something here is not right.

colu41 · 10-14-2011, 03:45 PM

Finally got time to pick up a new switch. Plugged it in and the fan doesn't even turn on now.

Do I need to wait for it to heat up or something before it turns on?

REP · 10-14-2011, 03:51 PM

Quote:

Originally Posted by colu41

Finally got time to pick up a new switch. Plugged it in and the fan doesn't even turn on now.

Do I need to wait for it to heat up or something before it turns on?

Perhaps you missed my first reply.

colu41 · 10-14-2011, 03:56 PM

Quote:

Originally Posted by REP

There has to be a relay,contactor,sequencer ,something that puts line voltage to the heating elements and or fan.
This usually has a low voltage coil that the stat energizes on a call for heat.

This?

So what am I looking for?

**beenthere** · 10-14-2011, 04:18 PM

Post pic of inside of the furnace where the wires connect.

10-02-2011, 12:38 PM	#1
colu41 Newbie Join Date: Jun 2011 Posts: 22	Mobile Home Furnace Problem I have a mobile home with an electric furnace. Now I have a fan switch that is bad. BUT, when I hardwire the wires together, the fan obviously turns on, but blows cold air. Is there another problem? Or will the fan switch fix this also? The fan switch when bad last year also. Had a tech come in to diagnos but, found nothing but the fan switch. Any help would be greatly appreciated.

10-02-2011, 05:30 PM	#2
beenthere An old Tradesmen Join Date: Oct 2008 Location: PA Posts: 19,069	Mobile Home Furnace Problem Could be a heat sequencer is bad.

10-02-2011, 06:46 PM	#3
colu41 Newbie Join Date: Jun 2011 Posts: 22	Mobile Home Furnace Problem Where would that be located?

10-02-2011, 08:51 PM	#4
Master of Cold Member Join Date: Aug 2011 Posts: 729	Mobile Home Furnace Problem What is this fan switch that is bad? Is it the fan relay, or the thermostat?

10-02-2011, 08:58 PM	#5
REP Member Join Date: Jul 2011 Posts: 613	Mobile Home Furnace Problem There has to be a relay,contactor,sequencer ,something that puts line voltage to the heating elements and or fan. This usually has a low voltage coil that the stat energizes on a call for heat.

Mobile Home Furnace Problem