Furnace and heating

[niftypkg]

Furnace worked last year; can't light it this year. OEM 1971 Overlander. It was removed last year for a check up re: safety. Then worked OK. Fan runs. No gas to light appears to be the problem. Any advice?

[zenith]

it all depends on the furnace you have,is it a pilot lt, or ele.spark. ? haveing become an expert this weekend with my own furnance , trying to get mine to work found out it was an alignment problem with the sparker,and agusting it to 1/16 of an inch from burner it worked like a champ.troy

[sfixx]

Originally Posted by niftypkg

Furnace worked last year; can't light it this year. ...Any advice?

Not enough info provided. Troubleshooting needed. Search forums. Start from the beginning. Make sure the pilot is getting fuel. Can take a while for fuel to reach pilot especially after disuse. Obvious advice is run appliance nearest to furnace to get fuel in the line. Be very patient. More complex problems follow. May be the regulator is stuck shut. The valve can get gummed up. I cleaned mine and then replaced the gasket with a self cut one from a generic kit from NAPA. Should you be able to hear it snap open and closed with the thermocouple? It may also be a limit switch problem, or the vane. I've seen other posts address these problems well.

Good luck,

Steve

[Darol Ingalls]

If the furnace is original equipment, it is most likely has a pilot light. Does that light? If not, there is probably some blockage in the pilot light supply line or at the orifice. If the pilot light lights but the main burner does not, you may have a blockage at the orifice to the main burner. This requires pulling out the furnace "innards" to get to the gas tube that enters the burner from the rear. It's amazing how little it takes to plug that small hole. After you get the furnace working again, best advice is to fire it every month at least once to keep everything clean. Spiders and other bugs love propane and will seek out any small opening to get to it and build their nests. While the furnace is apart you should also check for wasp nests in the intake and exhaust ports.

[Smokin Camel]

Ask yourself a question that I asked myself before I even found out there are some defective furnaces in the early 70's. Do you really want to trust the heat exchanger in a 35 year old furnace? A defective combustion vent system or heat exchanger can be a carbon monoxide source.

I had an OEM (I believe it was the NT24) which I though about replacing then I found out about the recall which had happened a decade or two ago.

I replaced the furnace with a smaller suburban NT20s. It did take a bit of cobbling to get it to fit but revamping my AS is a hobby I enjoy anyway. The new furnace has direct spark ignition (DSI), I never have to mess with it. Manitenance is easy, it you don't clean it yourself and inspect the exchanger etc. you can always have a furnace tech or a steamfitter do it.

Since you have an older vintage trailer like I do please consider installing a monoxide detector (& an LP gas detector) & maybe repace the old firebox?

At the very least pay the $$ and have an expert look it over and test it. When my old one was test run just for giggles (we already knew we had a cross-over vent defect), we set off the detector from 6 ft away in a garage.

I leep bettter with a modern furnace that does not set off the detector

[Smokin Camel]

That is good avice you are getting about the wasp nests in the exhaust....also test you gas connections and valves with soappy water...just for grins. That just makes sure nothing has loosened up over the years.

[niftypkg]

Great advice that you all provided. I have a gas detector. The furnace was tested but I will remove it again. Thanks

[Smokin Camel]

One good peice of maintenance you may want to try: vacuum out the chamber, be careful of the nozzle. You can remove it and clean it with a very small copper wire, don't use steel or score the nozzle. Cleaning the points can be done with some emery but go gentle. I am glad to hear you keep a detector in your AS, it is cheap insurance.

[woodnhair]

`81 28 ft..............stove top worked, but weak. furnace was automatic ignition. mine has a circuit board and that was a concern but not the problem. no gas to furnace. traced supply and found oil [residue with propane] in line next to regulator. replaced line and everything is fine.

[lewster]

Originally Posted by Smokin Camel

One good peice of maintenance you may want to try: vacuum out the chamber, be careful of the nozzle. You can remove it and clean it with a very small copper wire, don't use steel or score the nozzle. Cleaning the points can be done with some emery but go gentle. I am glad to hear you keep a detector in your AS, it is cheap insurance.

NEVER, NEVER put anything thru a gas orifice!!! If is it clogged and can't be cleaned with solvents and compressed air, IT MUST BE REPLACED!!! This is standard procedure in the RV industry and is taught in every LP appliance certification class given by the manufacturers that I have ever taken.

An LP orifice is a precision drilled opening and NOTHING should ever go thru it except LP and solvents. This is a VERY important safety issue!!!!! Any miniscule change in the size or shape of this orifice can and will alter the shape and/or size of the flame and be a potential cause for overheating and operation of the appliance outside of its listed parameters.

DON"T DO IT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Smokin Camel]

I will go along with Lew, go with his advice not mine, this though I will admit to using a 28 copper wire on my previous furnace. Compessed air is best, if it is available. Something else was mentioned to me today about plugged nozzles. If you do not have compessed air available, as it is with most people, the "blast air" cleaner for cleaning keyboards will work.

The main thing I have found on a couple of occaisions, in the furnaces is piles of debris building up in the combustion chamber. Vacuuming that out is often a big chunk of what needs to be done. Don't air blast the combustion chamber. The mess would not be a fun thing and you could scatter debris into all kinds of places where it should not be, vacuum it and us a paint brush (artist type), if you need to sweep some parts.

[lewster]

Originally Posted by Smokin Camel

I will go along with Lew, go with his advice not mine, this though I will admit to using a 28 copper wire on my previous furnace. Compessed air is best, if it is available. Something else was mentioned to me today about plugged nozzles. If you do not have compessed air available, as it is with most people, the "blast air" cleaner for cleaning keyboards will work.

The main thing I have found on a couple of occaisions, in the furnaces is piles of debris building up in the combustion chamber. Vacuuming that out is often a big chunk of what needs to be done. Don't air blast the combustion chamber. The mess would not be a fun thing and you could scatter debris into all kinds of places where it should not be, vacuum it and us a paint brush (artist type), if you need to sweep some parts.

THANKYOU!

[PizzaChop]

Nifty,

Been there, done that! No matter how much you do, you'll still have a 36 year old furnace.

The new NT-30 is real nice. I put one in the '72 Overlander before I sold it and recently installed one in the '73 Sovereign. I have a few pics as well.