Furnace question

[69Silvrbelle]

Hi,
I have a 69/70 (title and vin says 1969, but in the Airstream spec sheet the interior looks like a 70)Overlander and the furnace that is in it is a NT22a and is shot, unless I can find lots of parts(mostly a combustion chamber). So, what do I replace it with? Do I replace it with a Suburban NT20sq or a Suburban NT30sp? Or do I replace it with something else? What would require the least bit of retrofitting? I would like to use the original ducting, but that looks unlikely with the 20sq.
Planning a complete refit with the trailer, and currently living in it with just electric ceramic heaters.
Thank you all for a look at my issue!
Al

[Heirstreamer]

Using an NT furnace would be a good choice. The Suburban line of furnaces of today will be a close but not an exact replacement. You'll likely have to do some sheet metal work to get the ducting to line up correctly. Good luck.

[DKB_SATX]

A new NT30SP furnace is smaller than the NT22a, so you'll have to build it a platform to get it up to the height of the intake/exhaust ports in the skin of the trailer.

You can build the platform as a plenum to attach ducts to, but you'll likely have to modify the ends of the ducts somewhat to get it all hooked up.

They're not particularly cheap, but have a lot of nice advantages over the NT22a. They're rated for a lower amp draw for the fan motor, and they're spark ignition rather than a pilot light.

[Dumpster]

Originally Posted by DKB_SATX

They're rated for a lower amp draw for the fan motor, and they're spark ignition rather than a pilot light.

Interesting. Perhaps it is flat out wrong, but my AS owner's manual suggests my 22 draws roughly half the amps of what an NT30 does; one of the reasons I decided to keep it. I always assumed that was why it was so much quieter, which was another reason. And as you already mentioned, $550 was the cheapest I could find one, which was the third.............