2014 300mp furnace

[Jbe199]

What’s up everyone, just picked up a very gently used 2014 300mp. Just a general stupid question I’m sure but I cannot figure this out. When I turn the AC unit to heat I can hear the furnace turn on for maybe 30-45 seconds but then it shuts off. I’ve read the manual and it says to make sure gas is on and try again. Is there anything else I should be looking for? Or is it a completely different operation? I appreciate any insight on this. Thanks!

[Essvar]

Originally Posted by Jbe199

What’s up everyone, just picked up a very gently used 2014 300mp. Just a general stupid question I’m sure but I cannot figure this out. When I turn the AC unit to heat I can hear the furnace turn on for maybe 30-45 seconds but then it shuts off. I’ve read the manual and it says to make sure gas is on and try again. Is there anything else I should be looking for? Or is it a completely different operation? I appreciate any insight on this. Thanks!

Make sure you are getting gas to the unit by lighting the stove. I always run 3 burners until the flames are clean.



Then when you try to run the furnace do you hear the igniter clicking or smell gas from the exhaust port? If no clicking or gas smell its possible you will need a new sail switch.



Try priming the lines first then report back

[Jbe199]

Originally Posted by Essvar

Make sure you are getting gas to the unit by lighting the stove. I always run 3 burners until the flames are clean.



Then when you try to run the furnace do you hear the igniter clicking or smell gas from the exhaust port? If no clicking or gas smell its possible you will need a new sail switch.



Try priming the lines first then report back

Thanks I’ll try that soon and see what that gets me

[Jbe199]

So I have propane going to the stove and still nothing with the furnace. It’ll just turn on for 20-30 seconds and then shut off. I cannot hear anything trying to ignite or smell propane. Although I am running the generator so I’m unsure if I would actually be able to hear it anyway. Any other suggestions? Thanks

[Essvar]

It’s most likely the sail switch. Replace and you should be styling.

[Jbe199]

So the furnace lit up one time but I haven’t been able to get it to ignite since then. I can see on the diagram where it says the sail switch is. Any insight on where I may start to look?

[Essvar]

Originally Posted by Jbe199

So the furnace lit up one time but I haven’t been able to get it to ignite since then. I can see on the diagram where it says the sail switch is. Any insight on where I may start to look?

https://m.youtube.com/watch?v=-g3_Y7MqChE

This is for an Atwood. Not sure which one you have but, this should help.

[Jbe199]

I believe mine is an Atwood as well. I’m going to take a look at it here in a little bit. I’m assuming it’s right around the blower motor then? Appears to be in the video.

[JRTJH]

Some Atwood RV furnaces have an exterior access door and some Atwood RV furnaces have interior access only. If you have a large door/access panel with the furnace exhaust vents in it, you don't need to remove the furnace to get to the sail switch. On the other hand, if all that's visible on the sidewall of your trailer is one or two "exhaust vents", then access is only possible from inside the trailer.... Not sure which style Atwood furnace you have.....

[Jbe199]

Originally Posted by JRTJH

Some Atwood RV furnaces have an exterior access door and some Atwood RV furnaces have interior access only. If you have a large door/access panel with the furnace exhaust vents in it, you don't need to remove the furnace to get to the sail switch. On the other hand, if all that's visible on the sidewall of your trailer is one or two "exhaust vents", then access is only possible from inside the trailer.... Not sure which style Atwood furnace you have.....

So I have two access points. The one outside seems to be more of what I need to get to though.

[Jbe199]

UPDATE
I found the sail switch and it was clean and had no lint/hair on it obstructing it. I can move the switch and hear it click on and when the blower turns on I can hear it click the switch as well. What should I look to next? Any ideas? Thanks

UPDATE #2
So I’m getting a flame sense fault looking at the ignition control diagnostics. Where do I look to from here?

[Essvar]

Originally Posted by Jbe199

UPDATE
I found the sail switch and it was clean and had no lint/hair on it obstructing it. I can move the switch and hear it click on and when the blower turns on I can hear it click the switch as well. What should I look to next? Any ideas? Thanks

UPDATE #2
So I’m getting a flame sense fault looking at the ignition control diagnostics. Where do I look to from here?

If the sail switch is working correctly you should hear the igniter clicking in attempt to light the gas. If you don't hear the igniter that's the next step, you should also be able to smell a little gas coming from the furnace before ignition.