Suburban NT-22A furnace

[mickeymoose]

I read that this furnace was recalled. I removed the furnace and saw the rubber hose that was the problem. It looks to be in good shape. My problem so far is that I can get the pilot to light and stay lit. When I kick on the thermostat, the blower starts, but I can never get the main burner to light. I assume since there is gas at the pilot, then there is not an obstruction in the line. The stove and water heater work and light up with no problem. Is there a sail switch or limit switch that need replaced. I would really like to not have to replace this furnace. Here is a link where i found some of the parts. Marksrv.com Suburban RV furnace parts

Thanks for any help.

[Silverwanabe]

Hi,

It could possible be a bad thermocouple or a clogged orifice

I worked on my nt-22a this past winter.
Replaced the blower motor and the rubber tube.
Runs like a champ. I do have a co/smoke detector.

I have the service manual if you need a pdf copy.

Greg

[azflycaster]

After the blower starts the sail switch needs to close to open the gas valve. That would be a good place to start troubleshooting.

[mickeymoose]

Thanks for the quick responses. I will try some more cleaning and troubleshooting tomorrow.

[Uberphotos]

I have the exact same furnace, while I did no not share your issue, I too checked to make sure the furnace was serviced after the recall (it was). I would recommend, just to be on the safe side, to purchase a carbon monoxide detector. Mine has never gone off, however, it is better to be safe than sorry.
Could you post an update once you have the issue resolved...this way if I do have the problem in the future, I will know how to fix it.

[mickeymoose]

Well I finally got it to work! I had to take it all out for the 35th time, which I have become quite adept at. I took off each wire and cleaned the contacts, I don't think that did much. What I did find was that when I took apart the silver valve that leads to burner and to pilot, there was a small valve cover inside that seemed to be stuck in the off position. I think it probably had a speck of something in it from sitting unused for so long. It kind of clicked out when I took it apart and it seemed to operate properly after that. I put the enitre monster back together and fired it up. It quickly lit the burner and began to heat.

On a hopefully correct sidenote, the fan continued to blow for about 1 minute after I turned off the thermostat the first time. Does it have some sort of cool down mode? It shut off after that minute or so. I restarted it with the thermostat and let it run for 2 minutes, then shut it down again. It again ran the fan a little bit extra after I shut off the thermostat, but it was not blowing hot air while shut off. I hope that is normal.

On a dumbshi* sidenote, I almost cut the tip of my finger off. I would have taken a pic, but I couldn't get the blood to stop flowing long enough. If you ever are wondering about the sail switch, and trying to see if it works by manually running the fan, don't try to spin the impeller with your middle or any finger. The shroud that surrounds it is very sharp!!

I guess the bloodshed was worth it, as the furnace works and I now have a very intimate knowledge of how the NT22A furnace operates. I also can move it in and out in about 3 minutes, two minutes with bloody knuckles and second degree burns. Also, I was able to move mine in and out without taking any cabinets apart. The calsp at the top of the cover is a little bit tight, but it works ok. The manual says that you need to cut a hole in the cabinet, but I luckily didn't have to. Who knows what I might have done if I had a knife rather than an impeller shroud!

If you have any questions about this furnace, just send me a question and I will help in any way I can.

Also if you have any questions about quickly running into your house to do emergency surgery all while keeping the blood off the floor so your wife doesn't notice, just ask away.

[azflycaster]

Sounds like a winner! Too bad about the finger.

The running after the flame goes out is normal. There is a thermal switch with the sail switch which needs to cool down and open before the fan is shut off.

[azfiredog300]

Where do you get the rubber tube from?

[TCHANNEL]

Happy New Year everyone,

My pilot light decided to barely light today....and then go out either by itself or when the furnace flame dropped out. I'm thinking the orifice is plugged. Where is the orifice on a NT22A?

Tim

[TCHANNEL]

Originally Posted by Silverwanabe

Hi,

It could possible be a bad thermocouple or a clogged orifice

I worked on my nt-22a this past winter.
Replaced the blower motor and the rubber tube.
Runs like a champ. I do have a co/smoke detector.

I have the service manual if you need a pdf copy.

Greg

Greg,

Could you send me the service manual pdf copy? I'm trying to sort out a weak pilot flame.

Thanks,

Tim

[garry]

Running while in the cool down mode is normal.

Normally 1 to 1 1/2 min.

[BMW Sid]

I too have the same exact furnace. The little cap for acess to lighting the pilot is way rusty, as is the rest of the heat exchanger. The furnace has worked perfectly, long as I keep the bees out of the exhaust.
Where do I get a new cap? and or a complete heat exchanger?
Seems the parts are kinda pricey.......

[BMW Sid]

I forgot to ask about the re-call. can you enlighten me on that?
Also, Greg: Can you send me a copy of the service manual too?
716-751-9415 or 716-525-4900
Thanks!

[oryxcrake13]

Hi,
I have the same furnace in my '67 Ambassador International- It doesn't work at all; the PO disconnected the blower, and the furnace is full of dirt/mouse nest. Looking at replacements in the $500-$1000 range, would it be worth it to try to get the furnace fixed? Otherwise I'm looking at space heaters for the time being.

I would love to see the owners manual!

[Lance M]

Originally Posted by oryxcrake13

Hi,
I have the same furnace in my '67 Ambassador International- It doesn't work at all; the PO disconnected the blower, and the furnace is full of dirt/mouse nest. Looking at replacements in the $500-$1000 range, would it be worth it to try to get the furnace fixed? Otherwise I'm looking at space heaters for the time being.

I would love to see the owners manual!

Hi from Texas,
Having a safe, reliable furnace is important. The NT22A furnaces were recalled for the rubber crossover tube. Your best bet is to buy and install a new modern furnace. No RV tech I know of would touch an old furnace from 1967. Good luck!

[redthies]

Did anybody ever get a copy of the service manual? I'm trying o get my N22 to light up. I have the fan working, but so far no pilot. I'm going to change the thermocouple and see if that helps. Anyone have a pic of theirs with the front cover off? There looks to be a pilot knob or something missing on mine?

[TG Twinkie]

Post a pic of what you have.

[Lumatic]

Originally Posted by redthies

Did anybody ever get a copy of the service manual? I'm trying o get my N22 to light up. I have the fan working, but so far no pilot. I'm going to change the thermocouple and see if that helps. Anyone have a pic of theirs with the front cover off? There looks to be a pilot knob or something missing on mine?

I can't think of one good reason to try and get this furnace working. It's not vintage, it's just junk and could be dangerous. There is nothing in the Airstream service manual about it. You would need a Suburban manual if one exists. Other's have been there, including myself, and it's just not worth it.

[Icyfingers]

Hi.
I know this might sound silly but I can get my oven knob to move from the pilot off position. I just bought the airstream (my first) and am trying to figure it all out Any help would be appreciated

[TG Twinkie]

Don't understand your question. Are you trying to light it?
Are you working on the furnace or the oven? ie title of this thread.