'74 Overlander furnace replacement

[Britbat]

Hi All, We bought the Shiny Beast in June, it's all original and I'm in the process of replacing the plumbing with Pex and waterless drain traps and I'm approaching the sink/furnace/fresh water tank area. With the cold weather I tried to get the furnace going but the pilot light will light but as soon as the T.stat calls for heat I get a big Poof and the pilot goes out. I'm aware of having a 40 year old furnace and I'm giving some thought to just replacing it which will give me more room to work on the plumbing and a newer/safer setup. Any suggestions on a suitable replacement? Any suggestions will be gratefully received. Thanks in advance, Vic

[idroba]

The Suburban NT 30 should be a pretty close replacement in capacity as well as size and location of the air inlet and exhaust. You might have to build a small platform for it, I believe it is slightly smaller than the one you have now, that is not as tall. Be sure to use all 4 of the heat outlets, even if you have to add one somewhere near the furnace. The more air you can move through those units, the better they will perform.

You are wise to replace it.

[tracker]

I replaced the original furnace in my 69 safari with an NT-30 I had read that during that era there was a recall on that furnace and since I was working on the floor under it anyway why not. it went easier that I expected, but keep the outer case from your original furnace you can use it . Look up "suburban nt-30 replacing nt-20 " by QUINCE and the reply he got from Aage their are some earlier threads on doing this also. Good luck.

[Britbat]

Thanks,
Is the case different in the way the ducting is routed?
Vic

[idroba]

I would be careful about the keeping of the old case and putting a new furnace in it. The venting of the circuit board which did not exist on the old ones but is critical on the new ones is one main concern. When I have looked at old vs. new cases and guts I noted differing venting near the circuit boards, the old case not having vents, the new one did.

Just a caution and my thoughts to keep in mind. I am also pretty positive that use of the old case would void the warrantee on the new interior, if it came to that kind of question.

[tracker]

Originally Posted by tracker

I replaced the original furnace in my 69 safari with an NT-30 I had read that during that era there was a recall on that furnace and since I was working on the floor under it anyway why not. it went easier that I expected, but keep the outer case from your original furnace you can use it . Look up "suburban nt-30 replacing nt-20 " by QUINCE and the reply he got from Aage their are some earlier threads on doing this also. Good luck.

Sorry if the info I gave was misleading. here is the reference that I used with no problems.

If you go to the members list and look up FOTOCHOP
about half way down page 7 of his threads you will find some listed "Pix of suburban nt-30 replacing nt-22".
It has very good information and photos.

by using the bottom half of the old case and blocking the vents on the new furnace it greatly shortens the install procedure. Good luck. Carl

[Sodbust]

Would not give up so fast,, as you have a 98% chance its just a wasp nest plugging up the air flow valve,, or dirty and dry blower motor bearings..

Myself I would much better clean and oil the older unit than trusting all the gizmos on the newer ones with computer boards.. Just call me old school,., ??

Sodbust