Heating Problems

tmartin24

Member
I have a 2012 Big Country. The blower motor will come on and blow cold air but the furnace will not light to heat the trailer. Checked breakers and fuses and cannot figure out what the problem is. Can anyone help?
 

Rickhansen

Well-known member
First, understand what is supposed to happen when the thermostat calls for heat: It would be best to have someone outside and someone at the thermostat to check these basic things. If you check your propane like mentioned above, here's the next steps to check.

1. The fan starts. It moves air through two separate blowers. One is inside, from the cold air return through the heat exchanger, to your warm air registers. The other blower runs off the same motor shaft and is for burner combustion air. It draws in outside air through the combustion chamber, and out the exhaust. Both the outside intake and exhaust are on the furnace cover outside.

--First, make sure both of these ports are unobstructed. Also make sure all of your heat registers inside are open and unobstructed. This is because there is a air flow switch that has to make before anything else will happen.

2. When the airflow switch makes, the control board will start the spark ignitor and open the gas valve. You will know when this happens because you should hear the ignitor sparking for about 15 seconds. If there is no flame detected, the control board will shut the gas valve and run the fan for about two minutes to purge the combustion chamber of gas, and then it will retry a couple more times before locking itself out completely. I think you have to cycle 12VDC power to the control board to reset it.

--Do you hear the ignitior trying?
--Do you smell propane?
--Did you hear it light, feel any heat at the burner exhaust port?

3. When the burner lights, the ignitor acts like flame rod. It has to be in the flame correctly, or it won't work. The control board will shut the gas valve and go into purge and lock itself out, or continue to burn until the thermostat satisfies.

I'll tell you that there is no real good way to troubleshoot and service these furnaces. You can do some limited checking with a volt meter if you can read schematics, but you can't see stuff work. They really have to be removed and put on a service bench by a tech to get very serious.

Hope this helps you gather some info, so we might get you working again. Post your results back
 

larryanddonnakeever

Past Oklahoma Chapter Leaders (Founding)
Everything Rickhansen said is right on the money. I might add once the furnace has tried so many times and goes into lockout the fan will continue to run. You must then reset the controls turn the thermostat off then turn it back on. If it fails again you need to contact a service person, if you aren't comfortable or not able to troubleshoot the control system. That is after you have checked the presence of gas. Good Luck
 

danemayer

Well-known member
In addition to being out of propane, opening the tank valve too fast can shut off the propane, as can a bad regulator.
 

olcoon

Well-known member
We had a similar problem with our Elk Ridge. Fan would come on...no hot air, then it would cycle off. It was still under warranty & took it back to the dealer. Come to find out the "brain"...circuit board had a problem, they had to replace it.
 

caissiel

Senior Member
Last Month one camper came to me with the same question about his furnace and I told him to check his tanks by closing them and opening them slowly. He was tickled that it worked as I said.
 

Ray LeTourneau

Senior Member - Past Moderator
Other than everything said in the previous posts, the only other thing is you may be out of propane? Once you close the valves on the LP tanks, take off the tank connections and re-install and re-open the valves slowly. You should hear a slight hiss of propane pressurizing the line. Open the main burner on the stove top and try lighting the burner. Got LP? Try the furnace again. If you had air in the lines, it may take a couple cycles to get the furnace going. Hope all works out for you. Let us know.
 

Urban350

Well-known member
Thought I would put this here as I am having heat problems. My furnace does work but the burner keeps turning of and on. It is -9c or 21f out and will not get the trailer above 16c or 63f. The fan never shuts off but burner will re-light after furnace cools of. All vents are unobstructed. I am running of the batteries 70% of the time the rest of the time the generator is running. Any help would be great.
 

brianharrison

Well-known member
Thought I would put this here as I am having heat problems. My furnace does work but the burner keeps turning of and on. It is -9c or 21f out and will not get the trailer above 16c or 63f. The fan never shuts off but burner will re-light after furnace cools of. All vents are unobstructed. I am running of the batteries 70% of the time the rest of the time the generator is running. Any help would be great.

Is the flame good while it is running? (strong and blue, will make a roar sound) or is it weak? (lazy and yellow - will make a breezy, possibly popping sound). Can you hear the ignitor trying to light? If not the control board sounds like the culprit. If you can it may be the gas pressure/supply.

Out camping right now? Anyone there with a similar unit/furnace. Swap out control boards?

A couple of additional things to check.

Brian
 

Urban350

Well-known member
Yes I am camping seems like not enough air flow and burner over heats and shuts off. Cannot easily see the burner on my furnace. Now that the sun is up the trailer has warmed up.
 

mesteve

Well-known member
I didnt see anyone mention the possibility of the high limit switch. That too will cause these symptoms. Happened to us last spring...
 

Rickhansen

Well-known member
Urban,
I will go 100% with 'mesteve' on his his comment. Something is causing the high limit to cycle the gas valve. There are two high limits on the furnace, the first one is an automatic reset (I'm guessing at about 140 deg), the second one is a manual reset (again, guessing at 160 deg) and will lock the burner out until you push the reset button. The most likely is obstructed airflow make sure all of your vents are open/unobstructed. After that I might be inclined to guess at a bad high limit switch. You might check the air temperature coming out of the nearest vent, if more than 120-130 degrees when the burner cycles, the controlling high limit is probably working properly and you know you have an airflow problem.
 
Had the same problem with our 2011 Greystone, after one year. Repairman replaced circut board with one Made in USA, says will last 3 years, repairman said that the original was from China and only good for one year.
 
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