Attwood Furnace air flow/limit switch error code

[Lemur]

My furnace has an error code of air flow/limit switch fault. The light blinks once every three seconds. The problem started after I ran out of propane. I re charged-the system with propane and it still did not work. The furnace would blow cold air and then shut off with the error code mentioned above.
I disconnected the power and hit reset button and this worked for a little while.
Now i cant get it to work at all.
I have read to make sure that the vents are clear??? Not sure where exactly to look.
2015 International Sterling.

Any help at all. Thanks!!!

[trvler]

Hi - I have a 2007 31' Classic with a Atwood 8535-IV furnace. Last month it stopped working properly - would run for about two minutes blowing cold air, and then quit. The circuit board indicated a no.1 fault (Air flow/Limit Fault). I dismantled the furnace blower (from the outside, without removing the furnace) and discovered that the problem was the sail switch was improperly placed, and rubbing against the outside housing (sticking, in other words). I fixed that, and all is good now.
Do you know what model furnace you have? If it is similar to mine, I might be able to walk you thru a repair.

Paul

[bickp]

How did you fix that? Mine is a 2019 with not much use. I removed the cover and the sail switch. There was a tiny bit of fuzz at the base but not enough to impede it's movement. To put it back in you have to feed the inside tip of the metal first.
It is not flush to the side but does tend to hug the side, maybe 1/2 ' of so would be my guess. Does that sound right?

[stprit00]

I have a new 2023 27ft Globetrotter and have had the same issue multiple times, always after running out of propane or otherwise not using the furnace for more than a few days.

When you turn the furnace on after a short pause you should hear the fan start and feel cold air blow. After a couple of seconds you should hear the clicking of the igniter firing. If you don’t hear the click of the igniter start with checking the sail switch for both mechanical function and continuity. If you have no access to a multimeter, you can field test since you should hear a quiet high pitch hum at the furnace when the sail switch is active. Once you determine the switch to be properly functioning skip the thermocouple and go straight to the igniter.

After several diagnostic tests on the sail switch, thermocouple and igniter I have found there is a poor ground connection between the igniter and the housing which prevents the igniter from firing. Ground is facilitated via the mounting screw. Unfortunate positioning of the igniter behind the inlet valve makes it difficult to remove. However, I have found I simply need to remove the screw and run the igniter switch base plate around against the housing and reinstall the screw to get a good enough ground. Once I have established a good ground I turn the furnace off at the control panel for a minute then turn it back on. Has worked every time.

Hope this helps.