Harman Accentra insert not feeding, then won't shut combust. fan off

[Harman-NH]

Hearth.com folks:

My Harman Accentra pellet stove insert has been working fine - we had some warm weather 2 days ago so I turned it to "Off" and let it shut down, which it did on its own. Today, I cleaned it, added pellets to the hopper and then tried to prime the burn pot using the "Off" and "Test" combo, per normal. The combustion and distribution blowers came on but the auger didn't move, and the status light was off. I then tried turning it off by moving the feed adjuster back out of "Test" without moving the bottom dial from "Off," and then the combustion blower came on, very very low, and just stayed on and wouldn't go off for 5 - 10 minutes.

I did a hard reset, and when plugged back in, all blowers were off. I tried again to prime the pot, and the same thing happened - the blowers came on, the auger didn't move, the status light was off - then, when I tried to turn the blowers off, the combustion blower stayed on.

Any ideas? It's almost as if it thinks it's still hot, even though it's stone cold.

 

[Lake Girl]

I'm not a Harman folk but ESP troubles? When was the last time it was cleaned? How old is the unit? I'm sure the Harman owners will chime in... patience! Welcome to the forum though...

 

[bogieb]

If either the firebox door or ash pan door were still open (even a little), the fans will go on but the auger won't feed. The fans also won't go off until it can tell that both doors are closed.

 

[alternativeheat]

It sounds like the board is not getting a vacuum signal, like the hopper door is open or the main door not sealed shut etc. It won't feed pellets as such. Make sure everything is closed up tight. Did you get the fines box cover back on correctly ? No pellets caught in the hopper cover gasket ?

Hah, I went through this one time to discover that the hopper door was wide open LOL !!

Edit: Bogieb and I must have been typing at the same time !

 

[Harman-NH]

The unit is about 7 years old - I've fixed some things recently (last fall, replaced distribution blower and circuit board) but otherwise quite the workhorse.

Yep, all doors are closed but we did have some issues with the vacuum system on the hopper not responding correctly a few years ago. I've double-checked the hopper lid gasket and it looks fine (no random pellet chunks hiding in cracks anywhere I can see), and the burn door is closed but maybe there's a leak in the hopper somewhere I can't see easily.

Thanks for the suggestions - sounds like I'll have to place a service call for this one. And thanks for the (warm!?!?) welcome to the forums!

 

[bogieb]

Dang, I was so focused on typing in my diagnosis to your issue that I forgot to welcome you aboard.

 

[bogieb]

It sounds like the board is not getting a vacuum signal, like the hopper door is open or the main door not sealed shut etc. It won't feed pellets as such. !

Yep, all doors are closed but we did have some issues with the vacuum system on the hopper not responding correctly a few years ago. I've double-checked the hopper lid gasket and it looks fine (no random pellet chunks hiding in cracks anywhere I can see), and the burn door is closed but maybe there's a leak in the hopper somewhere I can't see easily.

Definitely sounds like a vacuum thing, whether self-induced or something else confusing the system, that is the question.

 

[Bioburner]

Have you tried the dollar bill test on the door gaskets? If they are leaking that would create the fault for the vac switch to not close and allow the auger to start. Anything past 4 years of running and the gaskets can be the culprit. 5+ years a big probably.

 

[Lake Girl]

Other thing to check would be the line to the vacuum switch ... not cracked or split?

 

[Bioburner]

Other thing to check would be the line to the vacuum switch ... not cracked or split?

Sure won't hurt to check it for a possible blockage. Seems Harman keeps the hose away from major heat that causes the hose to deteriorate and fail prematurely.

 

[Lake Girl]

sounds like I'll have to place a service call for this one

Do you do your own deep clean or have the stove serviced by the shop?

 

[Harman-NH]

Thanks again for all of the suggestions - turned out there was a ton of ash blocking the exhaust system, and coating the ESP. It probably wasn't able to exhaust correctly, or sense the ESP, so it kept running and wouldn't feed.

I pulled it, banged out the stovepipe and got a ton of ash back down - I also removed the ESP service panel and a ton of ash fell out of the side port. So I vacuumed all of that area out with a flexible tube vacuum adapter, really got it cleaned out, and then reassembled and bam! it worked again.

Thanks for all of the suggestions - these pellets are producing a ton of fine ash (much more than the same brand last year), and I guess it all just caught up with me. Ash is more than just an annoyance with extra pot cleanings - it can actually shut down your system over time!

 

[Bioburner]

Good majority of stove issues are cleaning related. Good to here you got your stove going on your own.