View Full Version : Furnace won't ignite .. Here is a tip...

10-06-2010, 04:48 AM
The furnaces in our rigs are kind of temperamental.. at least ours is. Every year or so, ours won't ignite.. I pull the furnace out and the problem is soot. This same thing happened to me a few weeks ago when I started to get the rig ready to head to Texas for the winter. I got my tools together to pull the furnace out and got to thinking, all I am going to do is blow the soot out of it, so what would happen if I took my air compressor, set it on 100 psi and blew air in through the intake port on the outside of the trailer.. I gave it a couple of shots of air, went in and turned up the thermostat and it ignite and has been working fine ever since. You might want to try this before you pull yours because it won't ignite.

10-06-2010, 11:51 AM
We did the same thing when we ran into trouble with the water heater. New coil quit working and the flame wasn't right. Had a tech come out to the site and discovered they had put a crimp in the gas line when they took it off to replace the coil. While he was fixing it noticed lot of buildup in the fire box so out came the compressor and talk about a mess when that compressed air hit. :) Had soot all over everything. Used the compressor to clean up as well. SO maybe when changing the anode road may want to blow out the fire box while at it.

10-15-2011, 05:38 AM
My tip I posted on 10/06/2010 about using the air compressor to clean the furnace... well I have found better way.. instead of an air compressor.. use your leaf blower.. the tip almost covers the intake opening and give a stronger continues blast of air. My furnace would not ignite yesterday.. used the blower and you can't imagine the black rusty sandy looking that came out of it. It works fine now and no tearing the furnace out to clean it. Tip.. wear safety goggles as the "stuff" will get all over you and not good to get in your eyes.

I just read another tip (I have not tried it yet) instead of blowing air in the intake to blow the soot etc. out of the exhaust, you stick a shop vac hose in the exhaust port.. put your hand over the intake port and turn the shop vac on. It sucks the dirt out and doesn't blow it all over.

10-21-2011, 08:21 AM
My brain is still in sleep mode but could you tell me where all the soot etc., goes when you use your leaf blower or compressor on the exhaust side of the furnace? Maybe I'm not reading the post right.

12-16-2011, 12:43 PM
Just ran into the same problem. Blew it out with compressor as suggested and now it lights. Air goes in one hole and soot out the other. So stand to the side. Only problem now was no air flow at the vents. Fan was working. Pulled the grill off and then the face plate and there was a hole where there should have been a cap. (One of the slots that you could hook up air ducts to). Cap was lying on the side of the furnace. All the hot air was being blown right into the cabinet area. Crimped the flanges a bit and replaced it and now we have hot air at the vents.

On another note, has anyone or does anyone travel in cold weather with the furnace running so that the rig is warm if you make a lunch or rest stop? Mary thinks we should at least stop and turn it on an hour or so before we reach the end of day stop or before lunch.

12-16-2011, 04:39 PM
Frank I have thought about that not sure how your model is but mine when the slides are closed they come over the heat floor vents. Seeing that the bottom of the slides have that black paper type material on them I thought the heat may ruin the material.

So we have never done that, when we stop I open the slides ASAP and turn the heat on also usually plug in our two electric heaters it seems to be ok in about fifteen minutes.

12-16-2011, 04:45 PM
Frank also the day before we leave here in the freezing weather I plan to put everything back in the creek all the stuff that does freeze. What I will do I have a 30 amp service I put in here at the stick house so I will get my two electric heaters out and turn them both on one in the front and one in the back that should keep things from freezing.

Traveling the first two days or so in the maybe freezing weather with no heat once we leave so far has not been a problem nothing freezes inside the creek. Once we are set up for the evening usually around 4PM the heat is back on again.

12-16-2011, 07:09 PM
Bruce, we typically have two Pelonis heaters going when it gets real cold. They do a great job. At home when we get a freeze warning, I usually run one and turn on the tank heaters. Since it only drops below freezing for a few hrs that is usually enough. If it looks like a harded freeze I'll try both. Like you I ran a 30 amp line just for the Creek.

On this trip we ended eating out when arriving at a camp ground to give the rig time to warm up.

01-14-2013, 12:41 PM
Some time ago, I believe on the old message base, there was quite a discussion on changing the thermostat. Ours
has gotten to the point where it will not ignite the furnace. (Have not tried blowing out the soot, etc. yet). What
brand of thermostat was used? Need to do something about it now as it is COLD here in Texas today. HELP!

01-14-2013, 03:04 PM
If the fan is turning on, the thermostat may not be the problem. Before going to a lot of trouble with the thermostat blow the soot out of the heater. If it's like mine, after sitting unused, it takes a while for the gas to get to the igniter. I've had to wait several minutes before hot air started blowing. If you need a compressor give me a yell. I believe you are in Aransas Pass and I'm just up the road in Portland.

note: Somehow I was looking at the Larry's post as I made mine so I thought he was having problems. I believe he is in Aransas Pass but don't know where you are.

01-14-2013, 03:35 PM
Just sitting around so searched the posts for the post you mentioned. Didn't find it but did save it to a wordperfect file at the time. Will convert it to Word then try to PM it to you.

01-22-2013, 12:26 PM
I changed our analog thermostat out with a digital one years ago. The analog accuracy range was + - 8 to 10 degrees.. our digital is + - 1 degree .. we love it. I have done several for others. I have not done one for a few years now, but the last time I still had to add a little switch to the thermostat casing to control the high fan setting on the AC. I think I have pictures and direction someplace on how to make the conversion if anyone would like them.

01-23-2013, 07:57 AM
You might check and make sure you have a good battery as I think the furnace depends on 12v from the battery more than from the converter. JMO


03-09-2013, 04:23 PM
Well thanks for saving me $100.00 not my furnace but the hot water would not light on gas, I thought what the heck blew it out problem solved thanks!