Furnace quit working

[Cujonaut]

Originally Posted by Nukeproof

Any updates on replacing the igniter board? I’m having the same exact problem you’ve outlined above. I ran out of propane in the middle of the night and it hasn’t been the same since. The blower will turn on for about 30 seconds and then turn off (there's no ignitor clicking sound and all the vents are open and unobstructed). I reset the switch 3/5 times and still nothing. I’ll check the sail switch next. Trailer is new, less than 6 months old.

Thanks in advance

I pulled the entire furnace out and checked the sail switch, gas valve and gas valve solenoids. Everything checked out, I put it back together and it started working. I put some lube on the sail switch in case it was getting stuck. I've got a new igniter board coming in the mail in case it starts acting up again.

Your problem sounds like it might be a bad or stuck sail switch, that or the board could be bad. If you never hear clicking or smell gas at the exhaust vent the board never gets the all clear to start the ignition process.s

[Cujonaut]

Originally Posted by Nukeproof

Any updates on replacing the igniter board? I’m having the same exact problem you’ve outlined above. I ran out of propane in the middle of the night and it hasn’t been the same since. The blower will turn on for about 30 seconds and then turn off (there's no ignitor clicking sound and all the vents are open and unobstructed). I reset the switch 3/5 times and still nothing. I’ll check the sail switch next. Trailer is new, less than 6 months old.

Thanks in advance

My furnace finally quit for good so I replaced the igniter board and it fired right up. Based on recommendations from a few folks on this site I bought a Dinosaur Electronics board. "Dinosaur Electronics FAN50PLUS Universal Igniter Board with Fan Control". Looks almost identical to the Dometic board it replaced except it has a 5 amp fuse on it. I'll let you know how it works out.

[Kim Gass]

Well here we are in Nevada bound for home We have just ten days to do that and the furnace doesn't even try
The thermostat has new batteries and there seems to be no resistance on the wires that feed the Attwood furnace
The furnace has an outside vent but no access outside. Inside is a panel with ductwork
The circuit breaker is good
Where else should we look? We did buy a Pelonis ceramic heater but if we have no hookups on the way home it will be cold
195 RB

[JimD]

Originally Posted by Kim Gass

Well here we are in Nevada bound for home We have just ten days to do that and the furnace doesn't even try
The thermostat has new batteries and there seems to be no resistance on the wires that feed the Attwood furnace
The furnace has an outside vent but no access outside. Inside is a panel with ductwork
The circuit breaker is good
Where else should we look? We did buy a Pelonis ceramic heater but if we have no hookups on the way home it will be cold
195 RB

Furnace is a 12 volt device so is protected by fuses and not circuit breakers. Check your fuse panel and if that fuse is OK, the next troubleshooting will need to be done at the furnace. There needs to be 12 volts at the thermostat in addition to its battery power.

I attached a couple of docs that may give some insight.

[steveajohnson]

Hi Jim, being an electrician maybe you can help me. I have a pinnacle with an Atwood furnace that is giving me fits. I reset the switch on top of furnace and it will fire and work until it reaches temp on thermostat, after it shuts off it will not start again and trip the reset switch. Any ideas, thanks Steve

[JimD]

I'll give it a shot. From what you state, the furnace will only complete one cycle and then require the reset button be pushed before it will allow another cycle to start.

A couple of questions:

1. Is the thermostat actually shutting off the furnace or is the furnace going into an error condition about the same time the room has reached the desired temp? Probably could test this by only leaving the furnace on for a brief period and then lowering the thermostat to force it to start its shutdown cycle.

2. Can you hear the burner operation? The question is does the blower continue to operate after the burner shuts off? This is a requirement to cool down the furnace and clear all gasses that may exist. If the burner and blower shut down at the same time I can see why the reset function would kick in.

From what I know about these furnaces is that they have a lot of safety features. If it overheats there is an overheat thermostat that opens shutting down the gas. If it doesn't have enough airflow, the sail switch will kill operation. As long as the thermostat is calling for heat the furnace will stay lit, there is no up-to-temp thermostat in the furnace, like a water heater, that cycles on and off regulating temperature.

The big question is what is causing the board to lock down in a total shutdown condition requiring a manual reset. The board is probably smart enough to recognize the overheat thermostat has opened up.

I would make sure there is no blockage in the vents or hoses feeding the vents if you can see any of them. Everything needs to be clean and flowing. Troubleshooting this without access to the furnace will be tough. The best thing you can do is to listen to the burner and blower operation.

It is also possible the board may be going into the error when it shouldn't meaning there is no problem but it just errors out.

[sagabob]

Well it turned out the problem was a faulty propane regulator. Should have checked it first but now I know a lot about Atwood furnaces. LOL