Refitting NT22A Suburban furnace

[oxfletch]

OK, so somebody else took the furnace out. I've now fixed it up, and am going
to put it back - easy enough to slide in, and there's a metal lip at the bottom that slides over the metal cage it goes into.

Only thing is ... the combustion vent at the back still seems to be about 1 inch from the outer wall. Am I missing some fitting at the back, or is just not reinstalled correctly? I can't see how it could slide further back ;-(

Confused,

M.

[uwe]

Originally Posted by oxfletch

OK, so somebody else took the furnace out. I've now fixed it up, and am going
to put it back - easy enough to slide in, and there's a metal lip at the bottom that slides over the metal cage it goes into.

Only thing is ... the combustion vent at the back still seems to be about 1 inch from the outer wall. Am I missing some fitting at the back, or is just not reinstalled correctly? I can't see how it could slide further back ;-(

Confused,

M.

There is supposed to be a crossover pipe from the vent to the furnace, if i remember correctly. Part of it is made from rubber. You might try calling InlandRV.com, they have good information on the older furnaces.

[TomW]

Originally Posted by oxfletch

... Am I missing some fitting at the back, or is just not reinstalled correctly? I can't see how it could slide further back ...

I am fairly sure you have the same furnace and setup that I do. On mine, the furnace guts slide in to the case to a certain point, and then must be lifted/wiggled a certain amount for the hot air output portion to clear the manifold.

I do not believe you are missing any fittings at the back, but there are a few pix at my website (link in my signature) if it would help you to verify. A '72 parts furnace still sits in my shop if additional pix would help.

Also, one problem I had was that one time I thought I had both rails engaged, but in actuality, only one was engaged (the other was riding on top of where it was supposed to go). The furnace would not slide in completely.

Tom

[oxfletch]

Thanks to both of you. TomW, from your diagram (http://www.knology.net/~tcwilliams/Furnace.htm), you can see two pipes clearly, at the top left of the pictures. The top one is exhaust, and the lower is intake. The intake rubber "gasket" just about touches the wall (but not very well), but the exhaust pipe (with the "cloth" type gasket on it) is still an inch away from the wall, which seems like a big problem to me (don't want the exaust gases inside thanks ;-))

uwe, is that where you meant there's a rubber pipe? Or you meant the one lower down connecting the blower into the furnace? (replaced that already ;-))

Thanks.

[3Ms75Argosy]

I just replaced my furnace. There is a cone shaped rubber gasket that mates the exhaust with the outside hole. I just threw mine away!

You might be able to get the new outside flange cover. It has two "pipes" that sleeve over the exhaust and intake pipes from the furnace.... however, I think the new ones have equal length pipes. You may have to trim the old one back...that probably is fairly easy though.

Make sure there are no hidden holes in your combustion chamber (iron manifold). I found some that allowed the flame to burn "almost" through the metal under the furnace.
Good luck!
Marc

[uwe]

What Marc said......

[MontanaArgy]

I just finished replacing my suburban furnace, 1976 version, NT 20 I think. Still have it if you want parts. There is a cone shaped rubber fitting which joins the intake tube to the outside cover, and a metal tube which joins and adapts the exhaust to the cover. The exhaust will give you about an inch more length. It may still be attached to the outside cover. Check to see if it isn't attached to one end or other of the exhaust tube. Could be just stuck on there.

I went through all the effort of fixing my old one up then found the pilot would light without depressing the "red button". Finally figured out the gas valve was leaking enough to keep the pilot burning brightly all the time. Gas valves are not available any longer, so ended up replacing the furnace in the end anyway. Sleep better too!

PM me if you want my parts, no charge. I will be away for a week, headed to Boise if that is anywhere near to you.

[Chuck]

this may be what you're missing:

check this thread: http://www.airforums.com/forum...ight=sneakinup

this flange fits in from the outside of the trailer, screws into the collar around the exhaust tube of the furnace, compressing the rope gasket, and squeezes the whole thing up tight against the interior and exterior walls of the trailer.

as you can see from the pics, its about an inch deep, so that might be what you need. good luck finding one, though. I couldn't, even from Suburban, but was lucky enough to find one from a "parts" furnace from another fourm member.

the part is shown clearly in diagrams from the nt-22 manual, if you have that, or the service manual for the airstream. (that section of my service manual is basically a re-print of the suburban manual).

[juel]

Speaking of furnaces, has anyone installed the LP/CO detectors themselves? Camping World wants $102.00 each to install. I have 12V plug-in outlets all over the Argosy. Could one of these be re-fitted for installation of this detector?

[MontanaArgy]

Oxfletch the pictures/parts in Chuck's link are what I have if you want them. Rubber connector for the intake too. I would bet that is what you need.

[oxfletch]

Originally Posted by MontanaArgy

Oxfletch the pictures/parts in Chuck's link are what I have if you want them. Rubber connector for the intake too. I would bet that is what you need.

Oooh. that's exactly what I need, by the looks of it. I'll just go check it hasn't
just fallen down the back somewhere ... if not, I'd love to beg / buy yours from you ;-)

Thanks!

[Chuck]

I found a .pdf version of the manual that I downloaded from somewhere on the internet....pages are mixed up, but its all there. lets see if the forum allows me to attach it. 1.2mb

if not, I can e-mail it to you.

[mimiandrews]

Thanks, Chuck, for posting that Suburban manual as a pdf. I downloaded it yesterday, and it's just what I need.

[jyobp]

If the offer is still open, I would love to get a copy of the manual for my furnace. I am experiencing the pilot not staying lit. I have replaced the thermocoupler but am still having problems. The furnace worked fine until just recently.

Thanks.
Jim

[Lumatic]

The NT22a was recalled due to a problem with the crossover tube deteriorating and combustion gases discharged into the living area. I don't think it is a good idea to repair this furnace and may be dangerous.

[Kevin245]

Originally Posted by jyobp

If the offer is still open, I would love to get a copy of the manual for my furnace. I am experiencing the pilot not staying lit. I have replaced the thermocoupler but am still having problems. The furnace worked fine until just recently.

Thanks.
Jim

Hi Jim,Click on the link in Post #12 of this thread, or here for a copy of the manual.

Pix of Suburban NT-30sp replacing NT22 - Page 2 - Airstream Forums


We pulled ours back in the Spring, stripped the carcass and threw the remainder of it in the metal recycle bin. Will get around to installing something more current one of these days.

Kevin