Furnace won't light

[Slim]

I have a Suburban Mod NT-16SEQ Furnace in my Scamp that will not ignite. When the thermostat is turned up, the fan comes on and then eventually goes off without the burner igniting. I suspect it is the electrode. It looks pretty simple to replace (two screws and one contact). I have not worked on furnaces before, and the closest RV service is 100 miles away. Any thoughts or suggestions would be appreciated.

[Darwin Maring]

See if there is an access plate that will allow you to look inside the burner compartment and see if is full of water. Mine was and I got the water out and it worked OK.

[Gerry]

Is this problem when your hooked up to shore power or just with Battery?
If the battery is low it will not have enough power to open the gas valve.
Can you hear the igniter clicking or see the spark when it is trying to lite?
If the answer is yes and your sure you have a good power (mine needs 12.4 volts min. in the battery to turn on gas valve.) could be sever other things.
1. Igniter is not close enough to where gas comes into burner chamber. This can be dangerous because gas can be building up in the chamber then Boom....
Can you smell gas???? If so and it is sparking just bend the igniter so it in the path of the gas tube.
2. the Fan is not turning fast enough to make the safty switch in the back of the furnace connect with will not allow the gas valve to turn on.
Try to locate wire and only if sure you've found the right ones you can jump them.
3. The gas valve is junk.

I've had all these problems over the years and all but #3 is a cheap fix.

[Slim]

Problem exists even when hooked up to generator (which is putting out sufficient voltage). Turn thermostat up, fan comes on, no click is heard, and cannot see spark. When it first happened, I tapped on ceramic of electrode, and it came on. Then when I tried again, it would not come on. Then I tapped on shield where wire from electrode passes through it, and it came on. Then tried again and does not ignite at all. So I do not think it is gas problem (never did smell gas), but rather electrical. Fan runs at normal speed. In the past it has worked fine with the position that the electrodes are in.

[Darwin Maring]

Did you check for water in the combustion chamber??

[Slim]

I did check, and it is dry.

[Darwin Maring]

Could the spark gap be to wide?

[Gerry]

I would say from what you discribed that it is the electrode. Darwin may be right and you can gently bend the electrod so they are 3/16 of an inch apart and in line with each other. If the ceramic is cracked then it is junk and replacement is an easy and inexpensive fix.

[tractors1]

Originally Posted by Gerry

I would say from what you discribed that it is the electrode. Darwin may be right and you can gently bend the electrod so they are 3/16 of an inch apart and in line with each other. If the ceramic is cracked then it is junk and replacement is an easy and inexpensive fix.

I vote the same.

[Slim]

Thank you all for the good information. Will check all of that out. Found this service manual online...
http://www.bdub.net/manuals/Suburban_Service_Manual.pdf