I have a Coleman gas furnace that won't light up after a huge blizzard we had. So now I've just got back in from shoveling snow, the house is cold.

Spoke to a buddy of mine and he told me to make sure the meter is clear which it now is, and the exhaust and intake pipes are clear.

Well, assuming the exhaust is the vent on top of the roof, that's twice as tall as the snowfall we had, but the intake I have no idea where that could be. Nothing on the side of the house but the drain for the condensation.

I do have bare metal pipe vents on the roof, I always thought these were for sewer vents and those care most certainly covered. We live in a mobile home.

The furnace does react to the thermostat. When it does call for heat the furnace makes a buzzing, and I think I can hear gas flowing, but it doesn't light up (I can hear the flame sound when it does) and the blower never kicks on.

I'm not sure how to check the pilot light, I see a tiny circle window but nothing through it. I do know it's an electric start so I don't have to manually light it.

It's possible this did happen a few times before the snowfall, but it's always been solved by just turning the thermostat down and then up again and would maybe happen once a week, but it may have been happening more frequently.

Any help much appreciated!

 

When intermittent problems start with a gas furnace.... it's best to get it checked out before it gets too cold. Like anything else.... gas furnaces require maintenance.

Doubtful your furnace has a pilot unless it's very old. I need to know what you have to help you with it. A model number or pictures are very helpful. How-to-insert-pictures.

 

dgaa070bdta

It's from around 2000, serviced at the start of this year.

I followed the instructional manuals advice and on how to start it up, which is basically just turning it on and off again which I've done a few times, but this time I'm following instructions to a tee so we'll see if that helps.

EDIT: 3 flashes, "pressure switch failed to open".

 

You mentioned rooftop exhaust + lots of snow.
If the snow got into the exhaust line it could keep the pressure switch from opening.

Is there a cap over the exhaust line ?

 

The exhaust is pretty heavy duty and tall. If snow fell that deep enough to burry it I think my roof would collapse. But it was very windy and we got about 20" of snow so I suppose going up there and taking a look just to make sure is the thing to do.

 

The one thing you could do first is to remove the rubber hose that connects the pressure switch to the draft inducer. Clean the tiny hole in the draft inducer where the hose connects. The tiny hole is at the bottom of the fitting. A straight pin or tiny drill bit.

 

This thing? Removed the cap, seemed perfectly clean.

 

No, on the pressure switch. The that’s the gas valve.
The pressure switch is failing to close when it should. Test it with your meter, but the unit is likely not moving enough air through the heat exchanger to attempt ignition.
Snow has likely blocked something, or blown into the exhaust and plugged it.

 

That furnace uses the Coleman style draft inducer. The arrow is pointing to the fitting you need to check.

 

I don't see anything that looks close to that.

Edit, found it, that is a tiny hole, cleaned the other one out too, both look clear no change to the issue.

 

Went up to the roof, snow was higher than the vent, but wasn't covered, cleared everything out, but still no luck.

New pressure switch?

 

No, it’s likely doing it’s job. Or clogged.
Not too much to fail on them.

 

I give it a good going over with a pipe cleaner, seemed spotless. What else could I try?

I did get it running once, it ran for about 5 mins then shut off, then didn't start back up again with the same error code.

 

Next would be to check draft with a manometer.

 

Thanks, I think it's time just to have someone come out and take a look at it rather than me buying a pricey tool. If you think of anything else I can try until then feel free to let me know. It did start up a second time right now, hopefully it'll run for a few days until I can get someone out here.

 

I’m guessing that since the unit failed during a snow event, snow/ice has clogged the exhaust to an extent that the pressure switch can’t make.
The issue may just go away. Although it could continue to randomly come and go as well.

 

Yeah I can't help but think it was the snow, but it looks like my roof vent is intake and exhaust is in one. I cleared the snow around it, but it did have room to breathe before that. I then worked on the pressure switch, I blew down the tubes and cable tied a lose pipe. One of those two things worked because I've had heat for the past few hours. I think I might replace the pressure switch as it's an easy swap out and relatively cheap. If that doesn't help I'll call and get someone in to look at it.

But for now it appears to be working. Thanks for the help!

 

Loose pipe?
It may be a concentric vent. Post a picture.
I wouldn’t worry about changing random parts without good reason. Even cheap, it could be waisted money on something that’s not a problem.

 

Yeah the two tubes going from the pressure valve to the vent were fairly loose. So I cabled tied them over the barb fittings. Not sure if that was the issue but heats been fine all night now.

 

If those small rubber lines don't not fit snugly..... replace them.
There is minimal vacuum there and no loss is acceptable.

 

They do not fit snug at all. I'll replace them. Furnace has been running all day today with no issues what so ever, I did cable tie one of the tubes that was lose, I wonder if this fixed the issue... we'll see i guess. Thanks for your help!

 

Appointment made with furnace repair company. Replaced the hoses but having the same issue. Usually it can be resolved by just turning the furnace off and on again and then it'll be fine for a day or so, but this morning it won't work and can't seem to do anything to get it started. Anything else I can try to get this thing running again?

 

Is the inducer running? Check draft.

 

Not entirely sure what you mean by inducer. But I believe so, it makes a louder humm when heat is called for for about 30 seconds then shuts off.

I'm assuming I'd need a tool to check the draft?

 

Had a guy come out and take a look this morning. Our heat exchange has holes in it.

He said the entire furnace is done and will need to be replaced. $3300 for the new furnace installed with tax.

He also told me the compressor outside would need to be replaced because it's old and wouldn't work with a new furnace. This would cost $2800 installed.