What is the life of an OEM furnace?

[perryg114]

I was wondering what the life of an OEM furnace is? How long do they last and how so you know when it is time to change it out?

Perry

[Inland RV Center, In]

Originally Posted by perryg114

I was wondering what the life of an OEM furnace is? How long do they last and how so you know when it is time to change it out?

Perry

Perry.

That sort of depends on how much it was used.

Typically, when the motor fails, that's a good sign to replace the furnace.

But again, a motor can fail prematurely.

Another sign, would be when the furnace is remove, for a complete and proper cleaning, what is the condition of the combustion chamber?

Andy

[CanoeStream]

perryg114 -- what year, length & model Airstream are we talking here?

[perryg114]

81, 31ft, Excella II, center bath.

Perry

[68 TWind]

Like Andy said, lots of variables but even if the unit looks OK pay close attention to the heat exchanger. My old Trade Wind furnace worked but I let a buddy in the HVAC business look at it just be sure and fix a small micro switch. He found a hole internally in the heat exchanger. That would have allowed combustion gases to mix with warm cabin air-a potentially deadly combination. If in doubt, change it out.

[idroba]

30 years is a long time for any RV appliance like a heater. Often they just get unreliable, or they have a pilot light ignition system that is a PITA to use. A repair is often almost as costly as a new unit. On my '71 Caravel I was getting headaches when using the furnace. I changed it out for a spark ignition one and the headaches and much of the condensation on the windows went away. When I tore it apart I found it had a rusted through combustion chamber, very dangerous.

There is no real answer to the question, but in general I would change one out at about 20 years just because, and due to the possible dangers of a bad one.

[perryg114]

Well I may pull it out and inspect everything before using it. I hope I can get it out without having to pull the kitchen counter.

Perry

[pgr32e]

This is what I found when I pulled the front off mine last fall, joint failure and corrosion. Furnace was 37 years old......Phil.

[idroba]

A second post from me on the subject. I just now pulled the original furnace on my 22' 1975 Argosy. It did light, run, and heat, but I was not confident of it's condition. Good thing, because when I got it out I found that previous owner(s) had "repaired" and re installed it with great gobs of silicone seal, the wiring had 4 splices in each of the 4 wires, the Suburban recall on the combustion air tube had never been done and the cracks were "sealed" with silicone goop, and I probably dumped 2 cups of rust flakes out of the lighting and inspection hole. The furnace was unsafe, and the PO's repairs were done improperly. I had a replacement furnace of the same age, but of known good condition which I put back in for now.

So, in addition to the age and condition of the furnace, what the previous owner(s) have done is also an issue to be considered. Was it done right, and safe?

I had a cousin and his wife and baby daughter all killed in a (non RV) CO related furnace accident. They bought a cottage in the fall, used it for the first time and were never seen alive again. One PO of the cottage installed a furnace without venting it properly, but got away with it. The second owner made further modifications on the cottage which amplified the original problem, but never used the furnace. The third owner, my cousin, paid for it with his life and his family's life. I am not trying to be over dramatic here, but sometimes safety is a matter of little things going right, or wrong, and what someone else did to repair things.

Furnaces get old, and can need to be replaced even when they seem to be functioning. Heads up.

[perryg114]

Good reason for a CO detector as well.

Perry

[edglenn]

I'd like to replace my Surburban furnace from my '69 Overlander.
What furnace is compatible, and will fit under the sink, etc?
Any brands, models recommended?

[Inland RV Center, In]

Originally Posted by edglenn

I'd like to replace my Surburban furnace from my '69 Overlander.
What furnace is compatible, and will fit under the sink, etc?
Any brands, models recommended?

The same brand works great, and is compatible with the present Suburban furnace.

Andy

[idroba]

Originally Posted by edglenn

I'd like to replace my Surburban furnace from my '69 Overlander.
What furnace is compatible, and will fit under the sink, etc?
Any brands, models recommended?

Most new Suburban NT series furnaces are compatible with the older one you already have. The holes through the wall may even be in the same place. A little research will tell you the specifics. Check the Btuh rating of the old one and look for the same in the new one. Probably will fit with little alteration.

[edglenn]

OK. Thanks.
I looked at the Suburban NT 30's and NT 40's on EBAY.
I didn't see any info on my exisitng unit for the BTU's.
Is there a rule of thumb for BTU range?
It's a 27' Overlander. Is 30,000 BTU's too much?