Austroflamm keeps tripping high limit switch, what could be causing this

I doubt its the air sensor board, that only controls the auger and combustion fan speed. It the convection fan running good? The high limit switch is located on the convection blower right hand side. You can always try jumping it to confirm the failure mode.

There not much in that circuit besides the wire and the switch. Try jumping the switch.Maybe a intermittent mire between the switch and the motor/control board?

http://pelletstoverepair.com/IntegraTechManual.pdf

Err, hold on a bit Flammam,


The dust bunnies may be attacking along with the ash devil.

Dust bunnies in the convection blower and the ash devil in the heat exchanger.

Smokey
That may be a possibility, but the high limit switch is attached to the convection blower in these stoves. The OP stated that the "Fans are both running as they should". If the high limit was attached to the back side of the heat plenum I would tend to agree with you.

My 2¢ - the stove is overheating because of low airflow through the heat exchanger, unless the firing rate has increased somehow.

Jumping that switch is fine as a test for a short duration of time and always monitored, but I for one do not like running without all of the safeties engaged.

I'd be doing a full cleaning using all devices of pellet stove torture followed by the use of high air flow devices. Starting just before the air intake and ending just outside the vent termination. All grill work, blowers, fans, etc ...

Don't forget to check the wiring.

Dust bunnies and ash devils are viscous when attacking.

If after a really deep cleaning, I be willing to bet that the convection blower isn't quite up to its former performance and may be stopping leading to over limit trip. But one would have to be in the room when it happens.

I had one that would do that when the lubricant got low.

Yes, I know those units on the Austroflamm are much better than mine.

bke7 said:

Any thoughts on , if a slightly loose connection can have this much effect?

Click to expand...

Bad connections can be a problem anywhere and at anytime. Possible it is the culprit. But at least the stove is all set for a cold one.

bke7 said:

Any thoughts on , if a slightly loose connection can have this much effect?

Click to expand...

Yes, a loose connection can do that. Some of the snap switches on my stove are fed only 5 volts DC, so a loose connection would be a real problem. Higher voltages would be less sensitive, but not much.