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

[bke7]

Finally spoke to tech support at Lucky Distributors, the importer for austroflamm he explained the error codes and advised changing the high limit switch which I did but back to square one.
Stove runs great for a couple of hours then just shuts down giving the error code 2 which again is high limit.

Any possible ideas on what the cause of this is , could it be a faulty air sensor board?

Stove , flue, air sensor are all clean, no air leaks

 

[bke7]

Both high and low limit switches are new

 

[Flammam]

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.

 

[bke7]

Fans are both running as they should, I replaced both high and low switches just to be sure , again the same result.
Error 2 which is high limit .
Bizarre because the stove has run much longer and much harder than it is now.
Something is sending a false signal or stray signal,
Stove is now running perfectly , then will just go into shut down

 

[Flammam]

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

 

[SmokeyTheBear]

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.

 

[Flammam]

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.

 

[heat seeker]

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

 

[SmokeyTheBear]

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.

 

[SmokeyTheBear]

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]

Thanks for all the advise
I have the stove shut down and will commence a very deep cleaning checking wiring along the way.
Keep you up to date later today

 

[bke7]

Found a loose connection on 6 terminal ( high heat sensor) , just slightly loose and snugged back down, also the push connector on the air sensor was on but not clicked fully.
Cleaned the entire stove again , methodically
Just fired it up , running well
Temps below zero this evening so it should be a good test
keeping my fingers crossed , post result in the am

 

[bke7]

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

 

[SmokeyTheBear]

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

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.

 

[heat seeker]

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

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.

 

[bke7]

Three hours in running as it should.

Wife is much happier when warm.

When the Queen is happy there is peace in the kingdom

 

[bke7]

1 degree outside last night.
Stove is working the hardest it has worked all season and no high limit trip

It appears that the high limit issue is a thing of the past
May have been the loose wire or connection not fully engaged that was triggering the reading.
A comprehensive cleaning is always a good thing also.
Thanks for all the help