i just bought a 1987 22ft hilo.. it looks very clean and so far the only thing i cant get to work is the furance,,,blower wont come on..does anyone know how to tell if the thermostae is working??.thank you Paul.. albrightsville ,

The standard HiLo thermostat has a control on the bottom to adjust the temp. It has a on/off switch on top that is very hard to move from position to position. Make sure it is on and the temp control is moved all the way to the right. If it is on the furnace blower should come on. On that old of HiLo it most likely has a pilot light that needs to be lit. If the furnace blower did not come on when switched on, remove the thermostat and connect the two wires together for a test only. If the blower comes on, the thermostat is bad. If it does not come on, check the voltage across the two wired. Should be 12v. You can go to the furnace manufactures web site and with the model# and download the owners manual and it will have a troubleshooting section. If you post the make and model# here some owner who has that model will give you better info. Quite a few different make and models have been used thru the years. Hope this helps. If the above does not help get back here with what you tried and what the outcome of the steps were and you will get help. Welcome to the forum.

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Jim L & Faye
2805C
2003 Silvarado diesel crew cab
2017 Silvarado, crew cab 1500 6.2L gas w/ 8 speed tranny
central VA

thank you//have to get the model #,,and will post it.. tried the 2 wires together and nothing happened..I put a test light on them and it lite up.. really new at this thanks again.

Look up your model and make of furnice on the internet. Should be able to find a trouble shooting guide. Post again and we will help you.

know its a sururban ,,not sure which model ,one of 3 models..nt-12s..nt-16s and nt-20s..not sure which one. I have the installation manual..I dont have a 12v tested,,only a 120/220.. no way t o look at furnance , cover doesnt come off only front cover i think..sorry to bother you guys.. wont use it till spring but still trying to fix it.. (happy winter): IST trailer..cant wait to camp...

Here is some info from Good Sam Insider that might help you out.

How A Furnace Works:
- A thermostat summons heat via a circuit board inside the furnace.
- After a short delay, the board activates a dual-purpose blower, injecting air into the combustion chamber while also moving air thru the ducts.
- A sail switch closes, signaling that the blower has enough air for combustion to occur.
- A gas valve is opened, admitting gas into the burner inside the combustion chamber, where an electrode assembly produces spark.
- Combustion occurs and gasses are vented outside.
- A limit switch halts gas flow if temperature is too high or if the blower becomes inoperative.
- The thermostat controls furnace run time.

Troubleshooting Malfunctions:
The most common malfunctions are generally related to one of two items:
- DC voltage and/or gas pressure.
- If the fuse panel is ok, use a 12v DC tester to check for power in the wires leading into the furnace. This will ensure that you have an uninterrupted power circuit.
- Check voltage to make sure it is adequate - at least 11 volts. Compare voltage at the battery and at the furnace. In weak circuits, voltage may drop as much as 1 volt between the battery and furnace, suggesting larger wiring is needed or battery is not capable of holding a charge.
- If the voltage is good, the problem may relate to the furnace circuit board, a relay, faulty blower motor, or another component such as the thermostat.

I recently ran across this article and thought I would pass the info on. Hope it helps you out.

Bob

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2014 FR Heritage Glen 282RK
2013 F250 HD 6.7L Diesel
Formerly Owned: 1995 22D Fun Chaser & 2901L Classic

Mine had a switch that was only accessible once you open the access door on the outside... guessing it was some kind of "maintenance" switch... Naturally when I tried my furnace it was "off"

Also don't forget the fuse... start simple...

A small volt meter is available almost every where for ~$10... invaluable in diagnosing a mostly 12v system like your RV is...

***The contact under the thermostat switch also had a "layer" of rust and wouldn't make contact... small wire brush and a little contact cleaner fixed that issue...

thank you..will get a 12v testerll

I had my furnace die near the fall of last year.

If your fan isn't coming on, I'd bet electrical problem, however there is a circuit board on most units, and it's possible the circuit board has become defective.

You cannot disassemble the furnace unless you remove the complete unit from the rv.

I removed the outside vent first, then removed the gas line, electrical connections, and unscrewed it from the floor, and it lifted right out.

Once removed, the complete outter cover slides off as a complete unit revealing the electronics and gas valves.

I carried mine into my local RV dealer, and IMO, the price to repair was much more reasonable than if I had brought the complete trailer in.

They are able to test it right on the bench using a simple battery and propane tank, turned out in my case the gas valve was defective, and was a fairly simple repair.

thank you so much..I started to take the furnance out..but the weather is in the teens so I will wait until it warms up..thank you and all others who helped me.. Paul.. Pocono pa,albrightsville

Nobody has mentioned this, make sure the battery is fullly charged, even if you think it is leave it plugged in, mine wouldn't start up and I thought my battery was charged and it wasn't, that was my only problem

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58 nights camped in 2013
20 nights camped in 2012

Proud owner of a 2013 Jayco Jay Flight 28 BHBE

Everytime we have had trouble with our heater, it was because the propane regulator on the tanks went bad. We had this happen on both our 1997 21ft Towlite and 2006 22ft Towlite.

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Les & Patricia
2006 22ft towlite (replaces 97 21TL)
2006 Toyota tacoma pre-runner 4.0 L V-6 quad cab
w/ 98 chevy Powervision towing mirrors
2017 Chevy Silverado 1500 5.3 v8 (replaces Toyota)
2 Hobie mirage pedal drive kayaks