2016 ACE 30.1 Furnace Won't Start

[Kitten-Pappy]

I bought it 2 1/2 years ago and it was lightly used (the odometer rolled 1600 on my way home. I tried to turn on the furnace for the first time this morning and it wouldn't fire. I'm not sure if the previous owners ever used the furnace.

The Atwood manual says the furnace is installed with a valve shut-off switch in the off position. It gives instructions/safety precautions to turn it on but nothing on the location of the switch. Do I remove the vent and the outside panel/door to find the switch and it obvious once I'm looking at the inside?

Any precautions on closing it up?

[twinboat]

3 RVs and none had a furnace switch, except for on the thermostat.

[Mudfrog]

Found a wiring diagram showing a circuit breaker. On/off switch is printed directly above circuit breaker. Not sure if this means the circuit breaker is the switch or if there is another switch next to it. This was for Series 79 models but I would imagine other models have similar.

Being a schematic, it doesn't show a picture of its location but it's safe to say it's somewhere on the furnace box. I would guess it's accessible behind the exterior panel. Would need a screwdriver to remove the panel. Should be easy to spot if it's there. If not there, maybe from inside one of the interior cabinets or drawers.

Edited to add: My reply above might not be what the OP is asking about. The switch I'm talking about would kill power to the furnace and therefore keep the propane solenoid valve from opening. I wonder if instead of a switch, there might be a propane valve that needs to be manually turned on instead?

Kitten, does the blower come on when you call for heat? It's blowing but the furnace isn't igniting? For grins, is there a propane stove inside and if so, does it light?

[Kitten-Pappy]

Mudfrog, let me answer your questions first. The propane stove works fine. The blower comes on and I can hear what I think is the furnace burner trying to light. The blower stops after about a minute. The only valve mentioned in the operation section is the shut-off on the propane tank. BTW, I filled the tank on the way out Friday.

I found a similar (same?) schematic in the instillation manual for the AFM series furnaces and had the same thought. Is there a switch and a circuit breaker or is it a single switch that also acts as a breaker. If there is a separate breaker and switch the schematic should show both, if it was drawn correctly. But then, this wouldn't be the first mistake I have found on a schematic.

The temp is supposed to be low 60's this afternoon with light wind so I guess I will open it up and find out for sure. Maybe someone who has done this will chime in this morning. I will post a reply with what I find after I am done.

[Kitten-Pappy]

Opened up the panel yesterday. The switch is also a breaker. It was in the on position but I cycled it. No help, still ignites, goes out for 3 cycles then shuts down. I finally found a video that shows the location of the limit and sail switches on my furnace. Unfortunately, I don't have any electrical cleaner with me or any way to get parts until I get back home next week.

I think we will survive on the electric heaters we have with us.

[Mudfrog]

Originally Posted by Kitten-Pappy

Opened up the panel yesterday. The switch is also a breaker. It was in the on position but I cycled it. No help, still ignites, goes out for 3 cycles then shuts down. I finally found a video that shows the location of the limit and sail switches on my furnace. Unfortunately, I don't have any electrical cleaner with me or any way to get parts until I get back home next week.

I think we will survive on the electric heaters we have with us.

The fan running and then the furnace initially igniting indicates the sail switch is working. I doubt it's a limit switch since the issue happens so quickly.

It does sound to me like this has something to do with the flame sensor. Either it's not adjusted correctly, it's bad, there's a bad connection somewhere, or the control board it plugs into is bad.

[Kitten-Pappy]

I saw on another thread that 'old biscuit' is the authority on furnaces. I sent him a DM last night and got a response this morning. He suggested 3 things to look at.

Bad/dirty connections
Bad control board
Dirty/damaged/misadjusted electrodes

He said it sounded like it the electrodes to him.

[mytimeyet]

Same symptoms with my furnace. The igniter would light the burner but it would shut off after a moment, repeat 2 more times and then not try again until resetting the thermostat to heat. Unfortunately I did a couple of things at once, so the actual cure is still a mystery. I tweaked/cleaned the flame sensor and took the control board out after finding it a bit damp. Dried off and cleaned the board with a soft rag and compressed air, reinstalled, put the sensor back in place and all was well. As a pre-emptive measure I also ordered a dinosaur replacement board but that is still in the box.

Originally Posted by Kitten-Pappy

I saw on another thread that 'old biscuit' is the authority on furnaces. I sent him a DM last night and got a response this morning. He suggested 3 things to look at.

Bad/dirty connections
Bad control board
Dirty/damaged/misadjusted electrodes

He said it sounded like it the electrodes to him.

[laker]

had that happen several times on my 2014 ace, had to dry the control board out with a hair dryer or compressed air, water seems to be able to get in compartment . hope that helps

[SteveD]

A 2016 model heater that has seldom been used is almost certain to have crud built up in the 'pilot' valve area. At a minimum, you should open up the 'pilot box' and thoroughly INSPECT and CLEAN that area. Highly likely that the gas valve is just not feeding propane to the flame area. Mine is a good bit older (06), but I had replaced the heat box unit only 3 years ago and still had to open it up and clean it out again before I could get it working late fall last year. I had to completely remove the feed line from the shut off valve to the flame box and take it all apart. There was the tiniest particle completely blocking the flame orifice. Tapping it 'backwards' knocked the particle out and it works 'okey dokey' now.
Steve

[GordSClemnte]

I had the same problem but only at elevation. Probably above 5,000 feet.
I closed up the gap on the igniter, still in spec.
Has worked fine ever since.