Harman P43 Issues

[wildlandff18]

Hey guys,

New to the forum. I did some digging in here before I posted, but can't seem to find my exact issue.

The stove has been doing some odd things lately. Last week it randomly stopped feeding pellets while I had it set to "constant burn". I turned it off, let it cool down, scraped the pot, and did a restart. No issues since.

A few nights ago I turned it off and the combustion motor ran for almost 2 hours before it kicked off. Again, nothing too alarming but I noticed it.

So I finally had the house to myself today and I did an in-depth clean. Heat exchangers, scraped everything I could inside, burn pot, igniter area. Took off the blower cover and did what I could to the ESP probe (without removing it). The back of my stove is fairly inaccessible, but I was able to get the right panel off so I could clear out the feeder body. It was packed full of fines so I cleaned it thoroughly. I thought for sure that was the problem...

I closed everything up and started the stove. It kicked out pellets properly, and ignited with no issue. The combustion blower was running just fine. Once the pellets were lit, the feed motor stopped kicking on. The fire slowly died, and the stove never got warm enough to turn on the distribution blower.

I let it go out. Unplugged the stove. Plugged it back in and tried the test. It initiated both the combustion/distribution blower, but the pellet feed motor won't kick on.

I checked the pipe from the roof down - and it looks fine. There's some build-up in the pipe around the ESP. Did I trip a safety switch or something? Or could the auger motor be jammed?

Any ideas where to start here? The weather in MI is going to be mild for a bit, so I'll be able to make due with my baseboard heating for a bit. Thanks!

 

[miteclipse]

Hello

The combustion blower will run longer in constant burn. This is because the stove is hotter than if you used room temp mode.

Start with the hopper lid. Make sure it is fully closed. You can tighten the lid latch to make a better seal by turning the nut clockwise. Also check the door latch. Make sure the fine box and igintor cover screws are fully tight. If you have a ash pan latch, check that as well.

Do you have an oak? If so, make sure that is not blocked. Check the air flapper to make sure that moves freely. Make sure burnpot holes are clear. A blockage or something not seated would cause the stove not to feed.

Had this happen to me when I was a new harman owner. My issue was the igintor are was packed full of fines.

 

[jzm2cc]

Sure sounds like blockage in the exhaust somewhere. If stove cant develop enough vacuum auger will stop.

Have you tried leaf blower trick on chimney yet? Bypassing the vacuum switch temporarily might be insightful too.

 

[mikkeeh]

Make sure that all the panels and covers you removed to clean have been reinstalled properly. ie. Cover for exhaust fan behind the ash bin, cover for the fines box, make sure all gaskets are intact.

 

[wildlandff18]

Thanks for the quick responses guys.

@mite - All the seals are tight. Air intake flapper is working properly. I took the plate off the igniter and cleaned it out. No issues there. Right before it stopped feeding pellets the auto-ignite function worked properly.

@jzm - I like the leaf blower idea. I don't have a leaf blower though. Haha. How would I go about bypassing the vacuum switch?

@Mik - Is there a safety cut-off if the back panels are removed? I've left them off for now so I can see what's going on back there.


I was thinking about the pellet feed motor last night. It has made some pretty loud clunking noises the last couple of weeks. Not often, just once every other day or so.

Also, could the ESP probe be playing into this? Like an idiot I blindly jammed the scraping tool in the exhaust pipe and likely hit it. It's also pretty caked with soot. The other idea I saw on this forum was to manually test the pellet motor by installing a plug and putting it directly into the outlet.

 

[jzm2cc]

The hopper lid may have a safety switch depending on age of stove.

If you have a multimeter, measure voltage across vacuum switch terminals to see if its 120V when running, indicating switch isn't closing. Or just make a small jumper wire and spade terminals to plug two vac sw wires together. If you aren't familiar with electrical trouble shooting don't do this as you could shock yourself or damage control board.

 

[wildlandff18]

My hopper lid doesn't have a switch. Electrical issues are a weakness of mine so if I try any of this I'll likely shock myself.

*edit

Alright I was feeling lucky so I went ahead and jumped the two wires to the vacuum switch. Flipped the dial to "test", and everything kicked on, including the pellet feed motor.

So that narrows it down. Is the switch bad? Or could it still be a bad seal somewhere? I just checked everything again. I'll be damned if I can find anything that's not sealed properly. The stove is only 4 years old and was barely used before last winter.

 

[wildlandff18]

Well I got it. I didn't realize how easy it was to disconnect the vent pipe from the back of the stove. Should have done that from the start. I moved the stove to the side so I could actually get at it. Thoroughly cleaned the ESP. Made sure the little trap door on the side of the feeder was tight (pretty sure I didn't have it on there properly). Cleaned the bottom of the vent out. Kicked on the "test" and bam, everything works. Reinstalled the vent pipe, dumped some pellets in and it's back up and running.

I'll just have to get a new gasket where the vent pipe meets the stove. There was a small leak there when the pellets were igniting.

Thanks for all the help!

 

[miteclipse]

Awesome. You may be able to use high temp silicone for the leak. Appears that the culprit was the trap door wasn't seated correctly.