Heater not working

[motc777]

We recently were having problems with the AC/Heater in the pull behind. It's a dometic thermostat, analog. We replaced it just a day or so ago. Fixed a lot of the problems, but one remains.

I switch to heater, and I go outside by the vent, and I can smell the propane and I can hear the igniter clicking, but it never catches fire. The blower runs fine.

What gives you think?

[motc777]

Wild Card wrote:

motc777 wrote:

Wild Card wrote:
The 12v come from your ac unit through the thermostat to the furnace

That's the thing. I hear in the ceiling the clicking when I turn on the heat on the wall thermostat. Just the furnace is not kicking on.

If you dont have 12vdc between the 2 blue wires at the furnace then you need to check it at the stat. At the stat but not at furnace a wire got broke. If you have it at the furnace than there is a bad board or bad connection.

I went to thermostat on the wall tonight. Tightened up all screws for the wires. Furnace fired up and burning hot instantly! Thanks!!!

[Wild_Card]

motc777 wrote:

Wild Card wrote:
The 12v come from your ac unit through the thermostat to the furnace

That's the thing. I hear in the ceiling the clicking when I turn on the heat on the wall thermostat. Just the furnace is not kicking on.

If you dont have 12vdc between the 2 blue wires at the furnace then you need to check it at the stat. At the stat but not at furnace a wire got broke. If you have it at the furnace than there is a bad board or bad connection.

[motc777]

Wild Card wrote:
The 12v come from your ac unit through the thermostat to the furnace

That's the thing. I hear in the ceiling the clicking when I turn on the heat on the wall thermostat. Just the furnace is not kicking on.

[Wild_Card]

The 12v come from your ac unit through the thermostat to the furnace

[motc777]

dougrainer wrote:
There is a Black reset/circuit breaker button on the furnace case. I will bet you turned it OFF when doing your work. Doug

https://www.bing.com/images/search?view=detailV2&id=93A6DAF3B6DF306C35354CAD91371417ED927777&thid=OI...

Well, I have a Suburban furnace, and I think that one that is pictured is an Atwood. I've linked to the one I have.

https://i.ebayimg.com/images/g/m3sAAOSw88hamy7S/s-l640.jpg

See on the left, I have a switch like that and I made sure it was on.

[dougrainer]

There is a Black reset/circuit breaker button on the furnace case. I will bet you turned it OFF when doing your work. Doug

https://www.bing.com/images/search?view=detailV2&id=93A6DAF3B6DF306C35354CAD91371417ED927777&thid=OI...

[motc777]

Update:

We finally got around to working on this, due to the nice, sunny weather and mild temps.

When this started, the heater would turn on, and you could smell propane, and hear the igniter trying to come on, but no flame.

We totally removed it as recommended, and I checked the orafice. Totally crudded up with a bunch of ****. Blew it out clean, reassembled it.

Turned it on, nothing. Not even powering on. I then checked for good 12 VDC from the battery, but on the switch to the board, nothing.

Is it possible that during the disassembly, that the board just gave up the ghost, or do any of you know of something more simple to check?

FYI - no blown fuses, and there are no fuses on the board.

[BFL13]

Where we had trouble with smell of gas and clicking but no ignition was the metal screen with the little holes in it over the orifice outlet and under the ignitor, was all rusted out. Got a newer "burner" with the screen ok, and no problem with ignition.

Maybe not the same set-up as Doug is thinking of that needs a complete pull-out, but with ours you can get at a lot of it in place.

I had wasp nests plogging things up at first, but that cleared up by just cleaning the exhaust pipe. I can get the burner out, but do have to disconnect the gas line. It is awkward to get it out, but it does come out.

I did see a youtube where they had to wash out the wasp nest dirt way in back with the furnace out and hosed it all out, but thank goodness, I didn't have to do all that.

[wa8yxm]

ONly the burner assembly need be rmoved but on most RV's that is done from outside not inside as the burner assembly is OUTSIDE and yes you will have to shut off the propane and disconnect the lines

Now on SOME Trailers... it may be different. but look for a panel with vents (square one as I recall) and held in by screws

[dougrainer]

motc777 wrote:

dougrainer wrote:
Smell LP and hear Ignitor. Only thing to do is to pull the furnace and clean the burner and check the burner for mud nests. NO OTHER diag is needed until you pull the furnace. Doug

OK. The furnace is under a couch that I can lift up. Do I totally have to remove it from propane lines, etc, or can I just take the top cover off?

The COMPLETE furnace has to be removed. Disconnect the LP lines and the 4 wire 12 volt wires. Disconnect the duct plenums also and the outside vent. Once removed, you take certain panels loose to access various parts. WANT a BIG problem? Do it any other way and you will regret it. Doug

[motc777]

dougrainer wrote:
Smell LP and hear Ignitor. Only thing to do is to pull the furnace and clean the burner and check the burner for mud nests. NO OTHER diag is needed until you pull the furnace. Doug

OK. The furnace is under a couch that I can lift up. Do I totally have to remove it from propane lines, etc, or can I just take the top cover off?

[dougrainer]

Smell LP and hear Ignitor. Only thing to do is to pull the furnace and clean the burner and check the burner for mud nests. NO OTHER diag is needed until you pull the furnace. Doug

[garym114]

What is the make and model of the heater?
Only way to correctly troubleshoot the problem.

[DutchmenSport]

Oh disregard.... I was think water heater, not furnace.

Edit!