HVAC folks?

[Black walnut]

Do we have any HVAC folks in our forum that can offer advice on my problem?

We live in a '78 mobile home with a Coleman furnace that seems to have an issue. Although I've not done a proper trouble shoot it seems likely that our heating element is shorted. It over heats and smells hot. Hmm might be a controller issue come to think of it. Anyway any advice on replacement? How do I figure out how much furnace I need to buy if I have to go that route? Current one has a 19.2KW element and is 80 amp.

[JimD]

HVAC is something I don't do much with. My son had a buddy who works as a HVAC tech help him install a new heat pump but the most I've done is change a thermostat or hook up the power. We get some odor at work from dust on the heater elements, that would be a much more minor issue.

So with the caveat that I don't know much, I will suggest that if the element was shorted, I don't think it would overheat. At least it wouldn't put out much heat. And the breaker should trip. So it probably isn't shorted. I would try to see if there is a way to clean the heating element and if that doesn't solve it, I would call somebody.

In terms of a replacement, if the old one was adequate I would get one the same size. One option that seems like it could be DIY is a split system. Their effiencies are really high but they are heat pumps and most do not have backup heat for really cold weather.

[woodturner]

It over heats and smells hot. Hmm might be a controller issue come to think of it.

Overheating suggests a thermostat or control problem - the heater is not turning off when it should, most likely.

If you have an auto thermostat, check the battery, could be as simple as a low battery. If not, when it is overheating, check the control from the thermostat to the furnace and see if the thermostat is calling for heat or if the furnace is continuing to run with no call for heat.

The folks over at hvac-talk might be more helpful, but they tend toward the anti-DIY, so you would at best get general guidance.

If you could tell us a bit more about your unit, we might be able to provide more help. Not really familiar with that style of unit, is it different than an electric furnace installed in a house? Is it a furnace or a heat pump?

[unclecritic]

Are you needing to reset it or does it run and just smell hot?

First guess would probably be blower issue whether the motor is failing, capacitor getting weak, dirt build up on blower wheel causing poor airflow. Electric strip heaters usually have internal limits if the elements get too hot the will open, allow the elements to cool, and then close and re-energize. A failing blower motor will smell of burning electrical as well

Second guess would be collapsed ductwork. Some older trailer home's used what looks like really thick cardboard for duct, and over time it falls apart

Hope this helps

[Black walnut]

A wire shorted out. Now I need to figure out if the wire over heated before it shorted or after. I hope it was just a case of vibration rubbing a hole in the insulation which caused it to short out. Still I'm nervious that it never tripped a breaker nor did it burn the cartridge fuse that was supplying power to it.


Shows on end of where wire attached


Where it attached on the other end. This end was shorted out.


In this view you can see what is above the burnt wire. I think it rubbed on the terminals upper left.

[EarlinePassmore]

You should better take advice from some good HVAC contractor. they will c ome to your place and inspect the area and accordingly give you the idea for replacement system.