Furnace Recall (model number location)

[idahoan]

Hello-
I am new to the forum and already feel very welcome! I recently purchased a 1972 29' Ambassador. My wife and I are planning a fairly large restoration for this winter. With the help of previous threads I have already tackled the converter and other miscellaneous projects.
Yesterday I fired up the furnace for the first time. It seems to be cycling correctly and there is ample heat coming from all of the registers. After perusing some threads about the furnace I read about the possibility of carbon monoxide leaks.
Where can I find the model number location. I looked behind the panel and couldn't find anything? Also, if my furnace happens to be part of the recall what is my course of action? Can it be repaired?
Thanks!

[azflycaster]

The recall was for the NT-xx furnaces and here is a link to more information about it: Suburban furnace

Your furnace is very old and could have issue that would make it unsafe. Older furnaces can have leaks caused by rust. Inspect the unit carefully and always use a CO detector.

[idahoan]

Thank you. Just what I needed.

[RockyMobile]

Gents,
I'll be doing the exact same thing...testing and wondering. Recall paperwork was with my 'Stream. I don't know how to establish, quoting the recall.."with absoulte certainty" whether repairs were made. I won't be in a hurry to use without reassurance and will be delving into your link, Richard. Thanks!

[DKB_SATX]

The recall upgrade itself is easy to recognize, though you have to remove the furnace to check. The original crossover tube is some sort of hard rubber (that can crack, allowing combustion exhaust to mix with the heated air for the interior.) The replacement part (no longer available) is metal.

Even if you have the metal crossover it's good to check the integrity of the heat exchanger carefully, since they can rust.

[idroba]

I don't think that Suburban is supporting the recall any more. The furnaces in question are all very old and beyond the time that anyone can be expected to be responsible for them.

The Model number is generally on top of the furnace, may or may not be visible when it is in place, depending on how your unit was built.

The recall involved the crossover tube that took the air from the combustion fan to the combustion chamber. The original ones were rubber, black. The replacements were (at least on the ones I had done) rubber, but with a red stripe on it. They may have also had some metal replacement parts, but I never saw them.

In addition to the recalled issues, combustion chambers rust out, burners clog and fans fail.

The bottom line is that your furnace is very old, parts are not available for it in most cases, it requires lighting with a match, and a standing pilot light, which is a PITA. New ones are safer, usually take less 12 volt power and have electronic ignition.

I would highly recommend you budget for a new unit. Antique furnaces should be replaced for safety, in most cases.

[RockyMobile]

Sound advice. I haven't embarked on the removal and inspection of mine yet but feel prepared to junk the old one and gain 100% peace of mind. Which modern models lead the way for replacement?
Michael

[idroba]

For the least modification, the Suburban still makes furnaces with about the same footprint and often the same inlet/outlet holes so you have a new furnace in the same location and reasonably easy replacement. Not everything will be the same of course, the gas inlet is often in a new location, and the wires may be a little different, but still only 4 of them, a hot 12 volt line, a ground line, and two thermostat wires. Recently I have read here on the forum that some of the newer Suburban's inlet/outlet holes are in different locations than the old ones, requiring the holes to be re located, but I am not sure about that.

Someone else may chime in here with better recent replacement information on the one you have. I have only replaced the smaller 16,000 btuh ones in my smaller rigs recently, so I am not sure about the larger ones. Yours may be 24,000 or 30,000 or even larger. My 16,000's ones were direct replacements for my 35 to 40 year old ones.

[Minno]

We bought a suburban furnace for our '72 from Vintage Trailer Supply. It's a direct replacement for the original according to their web site. We cannot fully attest to that since the furnace was long gone when we purchased the trailer 3 years ago. However, the vent holes do line up exactly. You can see it installed in Little Girl here at post 271: http://www.airforums.com/forums/f185...-50967-20.html. From what others have said on the forums about the early 70's furnaces, you should remove your old one and replace it as they are quite dangerous.

Chris

[Lumatic]

I know the NT20a was recalled. Ditto the consensus to junk the old and get new. It's just not worth messing with. As an alternative to a new Suburban there are other more energy efficient furnaces out there. I think maybe Atwood makes one. There is at least one thread somewhere. You may be able to get a new Suburban NT30 from Palomino RV supply for about $350. Another alternative is a catalytic heater. The upside is no moving parts and no fan noise. The downside is you need to keep a window or vent open. The new ones have a low O2 sensor that will turn the unit off if it burns up too much oxygen inside the trailer. There are wall mount and floor stand models and will free up storage space that would be used by your traditional furnace. Since no or little electricity is being used it has an advantage for boondocking. Some folks have both.