Surburban Furnace Problem - Montana Owners Club

nosticks · 11-28-2010, 01:52 AM

My furnace has been operating properly, until this weekend. Here is what I have checked. Gas is plentiful and flowing to all appliances. The oven works, the water heater will work on gas, the refer will work on gas. None of these appliances are on at the moment. The 12v system is on converter and putting out the proper voltage. There are no fuses on the 12v panel blown. The thermostat is set to furnace. The thermostat is set to max temp. The blower operates for about two minutes, then stops. No ignition occurrs.

wingerphil · 11-28-2010, 02:32 AM

Dave,
We have an Atwood furnace in our's so not sure my experiences will apply to a suburban but...
I have had the same problem with mine on a couple of occasions. The first one was a bad "sail switch". This switch is located inside the blower housing and when the fan is blowing it closes the sail switch which completes the circuit allowing for ignition. $7.00 part and not too hard to change out. Mine was visibly "burnt" at the contacts.

Last month it started doing it again so had a technician look it over and he found the circuit board was corrodid. Our shower was leaking ever so slightly and dripping down onto the furnace and over time the water damaged the circuit board. He replaced the circuit board and I sealed up the shower.

On the Atwood's you can take off the outer panel (4 screws) and there is a red light on the circuit board that will flash a code for trouble shooting. When my sail switch was bad I could tap on the blower housing and the switch would come "un-stuck" and the furnace would light. Guess this was my "low tech" way of isolating the problem.

nosticks · 11-28-2010, 03:13 AM

Thanks Wingerphil. I suspect a sail switch or an ignition module. I am at a campsite and the dealer is exactly half way back home from here, but not open Sunday. I'm under warranty, but was trying to avoid an extra 100 mile trip later next week to drop the 5er off. I didn't saa anything simple like a reset. Surburban web site is for idiots as it has no usable trouble shooting data.

**Rondo** · 11-28-2010, 03:33 AM

Hey Dave- your're down in Florida-- what do you need a furnace for anyway???

Drifty1 · 11-28-2010, 07:22 AM

Dave I have had problems with the amount of gas flow. I could get the stove etc. to work but was not getting enough to supply the furnace. I would go to the outside vent for your furnace when you try to light it. If you feel any heat or hear the furnace lite for a second then go out the igniter is doing its job. I have found mine to have problems when I change bottles, I believe the internal check is lifting in the bottle if opened to fast and this will cut the gas flow needed to light.
I also had to replace the igniter on my furnace a year ago as it was corroded enough that it would only spark once and a while. I have a few photos of my burner front in the link on this post.
I wish you luck as I was have a few problems with mine last week when it was 15 deg in Anacortes WA.

SlickWillie · 11-28-2010, 10:31 AM

If you haven't tried yet, try switching to the other propane bottle.

noneck · 11-28-2010, 12:32 PM

If the curb side is empty, put the full one there and do as "SlickWille" suggests just to be sure the xover regulator is not messing up your flow rate. Furnace is the biggest flow demand device in the rig.

nosticks · 11-29-2010, 01:22 AM

Noneck, curb side is new and unused. I took it out and weighed it, 54 lbs., which is full. The street side was just filled and has been used about an hour on the oven and close to an hour on one stove burner. Other than my testing the water heater for a few moments and the refer for a few moments that is the total usage. The furnace is in what I believe is symptomatic of a condition called lock out. The blower runs almost exactly 2 minutes with no ignition. After three attempts to light it goes into "lock out". I was looking for an easy reset, which is probably what my dealer will do. I will post the end results.

stiles watson · 11-29-2010, 05:05 AM

I had a similar type problem. The cause was that the wire that ran to the igniter was shorting out and arcing, like a spark plug wire with a crack in the insulation shorting against the block. Replacing the wire solved the problem.

Ozz · 11-29-2010, 11:13 AM

Quote:

quote:Originally posted by nosticks

Noneck, curb side is new and unused. I took it out and weighed it, 54 lbs., which is full. The street side was just filled and has been used about an hour on the oven and close to an hour on one stove burner. Other than my testing the water heater for a few moments and the refer for a few moments that is the total usage. The furnace is in what I believe is symptomatic of a condition called lock out. The blower runs almost exactly 2 minutes with no ignition. After three attempts to light it goes into "lock out". I was looking for an easy reset, which is probably what my dealer will do. I will post the end results.

This sounds to me like a dirty flame rod, sometimes furnaces have the spark ignition and the flame rod as a combination, I haven't looked at mine, but I clean around 150 flame rods each heating season, by far the most frequent problem. Just take a scotch-brite pad and clean it. It will be the stainless rod that is in the flame when the unit is firing. It just makes a ground insiude the flame.

jliveit · 11-29-2010, 11:40 AM

Had the same problem on our 2011 turned out to be just what Drifty1 said, not enough gas flow doas the manual says on opening the gas bottles.

HamRad · 11-29-2010, 12:15 PM

On the newer models doesn't the control board have a "reset" button on it? I have the older type so mine does not have that feature. But I seem to remember reading on here about that feature. But my CRS prevents me from guaranteeing anything! Some of you know what I'm taking about!
HamRad

Ozz · 11-29-2010, 12:40 PM

generally a board cycles for a number of times, then locks out. Killing the power and restoring it resets it.

HamRad · 11-29-2010, 04:49 PM

Ozz,
Thanks for info. When my furnace had this problem it was the control board. Got a dinosaur replacement and was good as new....Maybe even better!

Dennis

jackel1959 · 11-29-2010, 05:17 PM

Dave,
Sounds like you already have a good handle on what is going on and what you will need to do to get it fixed. I found this link for trouble shooting that you might find useful in the future: Surburban Trouble Shooting

nosticks · 12-03-2010, 10:05 AM

Had to go back to the dealer today, all day both ways about 200 miles. Here is what they found. Furnace had to be removed from cabinet to gain unrestricted access. An internal wire had become dislodged. One that controls the electronic spark. Wire reconnected, problem solved.

Ozz · 12-03-2010, 10:44 AM

Glad you got it fixed, Bummer that you had to take it in, but... it's all good.

CamillaMichael · 12-03-2010, 11:25 AM

Quote:

quote:Originally posted by nosticks

Had to go back to the dealer today, all day both ways about 200 miles. Here is what they found. Furnace had to be removed from cabinet to gain unrestricted access. An internal wire had become dislodged. One that controls the electronic spark. Wire reconnected, problem solved.

Does not seem right that a 2010 model should be "falling apart." I wonder if merchants within the rv industry were required to go to the customer to address problems (instead of us having to go to them), quality control might be better. In any event, glad to hear you are operational again, nosticks.

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