No heat or hot water. Please help

[Shwthomas1975]

Hello. We recently purchased a one owner travel trailer. It's a 2003 26 foot travel lite. The gentleman we bought it from said he never used the furnace and rarely used the hot water heater.
The hot water heater works on electric, but not on gas. The furnace fan kicks in when I turn it on and it tries to light a few times (hear the click), then shuts off. I undid the gas line to the furnace and it is getting gas. All breakers and fuses are good. Stove works great and the fridge works great on either gas or electric.
Any thoughts????
Thank you in advance!!!

[enblethen]

SF series furnaces these are another very common RV furnace

[wa8yxm]

Can you take a photo of the area on the outside where the intake and exhaust are? Should be access there without pulling the entire unit out. If there is not .. Well add-a-panel works Will describe the panel to add.

[doxiemom11]

Our furnace has done that and one time is was a crispy fried little mouse in the furnace burner area, and the 2nd time it was a loose wire. We have outside access so could open it up and clean, check all connections, and it fired right up after the connections were clean and secure.

[camperdave]

If it's clicking (trying to ignite), it's not the sail switch. Definately sounds like gas flow issues, especially in light of the water heater working after blowing it out.

[AllegroD]

Shwthomas1975, Did you look at the floor of the closet to see if it can be lifted or if there is a hatch? Those two holes on the outside, are they in a larger cover that has screws?

[enblethen]

Did you locate the model number of the furnace?
In you case, you should have access from the interior of the rig.
Now it sounds like the ignitor portion of the unit. Circuit board, high voltage cable or igntor itself.

[Shwthomas1975]

Quick update. Hot water heater is good. Compressed air and it fired right up

Furnace not so much. No outside access except the 2 exhaust holes. And it’s tucked under a closet with the only access is the return air grate. So I opened that up and see the silver box (furnace). I can take the back panel off but that only exposes 2 wires connected by something. I think the guys are in front which ya backed into the cubby.
But, I did notice that I can smell gas through the exhaust outside while the fan is on blowing. I believe this rules out the sail switch as I believe that restricts gas flown this leaves maybe the igniter??? I here it clicking away a few times before shutting down but no fire.

[enblethen]

The sail switch could be issue with the furnace. You can blow out the furnace from the outside access, if it has one, with air compressor or can of compressed air. One my furnace the sail switch is located in the rear right side of the circulation fan.
Cleaning the water heater is pretty easy to do. I usually remove it completely. I have run it a couple times through my wife's dishwasher. You should remove the orifice and soak it in alcohol. No, not the good booze, just rubbing alcohol.

[newman_fulltime]

Old-Biscuit wrote:
Seco:hnd thought...........
Brand/Model of each?

Where is SIR dougie when one needs him !!!?!???

[Old-Biscuit]

Second thought...........
Brand/Model of each?

[BarabooBob]

Obstruction in the air supply or exhaust. Mud daubers shut down my furnace with only about 10% obstruction in the air intake. Never had a problem with water heater because I never used it.

[midnightsadie]

if you give up? don,t take it to a dealer. call a mobil tech ,they come to you ,you get to help,and learn. cheaper. smarter. a dealer will just throw parts at it till it works, or you run out of money.

[wa8yxm]

First the comment about air in the line.. ****. Any air in the line would be blown out the first time the furnace or water heater tried to light.. Those are MAJOR gas suckers.

Now one possible issue is the excess flow valve. TUrn off Propane then turn it on very slowly. like quarter turn at a time if you hear gas flow. stop continue when you no longer hear it flowing. Till it is FULL OPEN

Regulator not opening fully (As I said the devices not working are major gas suckers)

But frankly I'm doubtful of those

Clogged orifice. Fairly common. removing and cleaning fixes. A spider likes to nest in 'em.

Bad control boards or solenoid valves is another option. But you need to do a full diagnosis flow chart and I don't have it on this computer.

[Shwthomas1975]

That's a good idea. I'll try some compressed air tomorrow. The hot water heater is easy to get to, but the furnace is quite the pain lol.
I'll keep yall posted
Thanks again!!!