Slow Auger Feed on Harman P43

[PennPellet]

Hi All -- long time no post.

I've had my Harman P43 since Winter 2014/1015 with no problems. I currently cannot use the pellet stove because the stove is feeding pellets very slowly. The stove starts normally, it starts filling at a normal speed, then suddenly starts feeding very slowly. It feeds so slowly that the initial flame is super small, barely an inch in height.

There are no blinking lights on the side and I haven't changed any of the settings recently. I have tried running the stove on both stove and room temp modes.

The stove is relatively clean, i made sure every inch was clean since the issue. The fines box in the back is empty--- all doors seem closed tightly. I also cleaned the ESP sensor. I haven't cleaned all of the exhaust yet, but I can't imagine its gotten too dirty since I last cleaned it in the summer. I also haven't done the dollar test yet...

From reading old threads, I've heard people mention a dirty ESP sensor, improper draft, leaky door, fines box, circuit board failure. --- i do not know where to start!

 

[smwilliamson]

Stove temp or room temp?

 

[PennPellet]

Stove temp or room temp?

Both, but normally I use room temp.

 

[smwilliamson]

Replace the ESP

 

[jackman]

I would check it in test mode. If it passes then try running it on stove temp, turn the feed rate up to 6, and turn the temp dial up to about 90 and see what happens.

 

[bogieb]

If your room temp probe became disconnected it will have an affect in room temp mode and may have an affect in stove temp; my P61a has to have the room temp probe properly attached to run correctly in both modes (been there) - other people report their P61's don't need the probe in stove temp mode. If it is attached properly, the probe itself might be bad. I think they are fairly inexpensive to replace. I believe someone here had that issue last month or so and found either their cat/dog had chewed on it or somehow got a nail hole in it (as you can tell, my memory isn't the best - LOL)

As others have suggested, it could be the ESP. Although it seems a bit early for that to crap out. Both of my stoves are older and never had an ESP issue even though I have never done anything but run a brush over them while brushing out the exhaust. Doesn't mean it couldn't happen, just seems early.

 

[PennPellet]

How could my room temp probe get disconnected? I know for sure it hasn't been messed with since install

 

[Bioburner]

Who had the issue and found it to be the exhaust to have had a fury rodent trying to take residence and causing the low fire issue? Even though they had just cleaned it two weeks before
Check and make sure everything is clean as a poor breathing stove is not a happy stove and try a hard reset.

 

[PennPellet]

I would check it in test mode. If it passes then try running it on stove temp, turn the feed rate up to 6, and turn the temp dial up to about 90 and see what happens.

I tested in test mode, normal.
I tried in stove mode,90 / feed 6. Same problem as before.

And more ideas?

In fact the fire was even weaker this time around.

 

[jzm2cc]

Check the auger roller is riding on the feed arm cam properly. I've seen stoves that weren't opening the feeder plate fully because roller wasn't riding on cam properly. A quick bend to cam corrected low feed rate and small flame issue.

 

[bogieb]

How could my room temp probe get disconnected? I know for sure it hasn't been messed with since install

Poltergeist? I don't know, but it is at least easy enough to check and test. My P61a has done that before, I live alone so all I can guess is while I was cleaning back there I bumped it. the probe tip itself never moved, so I was lucky I found the issue without spending any bucks on parts I didn't need. Oh, and it still looked connected, just slid a bit so there wasn't full contact.

 

[PennPellet]

Check the auger roller is riding on the feed arm cam properly. I've seen stoves that weren't opening the feeder plate fully because roller wasn't riding on cam properly. A quick bend to cam corrected low feed rate and small flame issue.

I have a feeling this may be the issue. I would have to empty the hopper to do this, right?

 

[Bioburner]

Cam is at the back of the stove
Could be something stuck in the auger flights that slows the feed too. I just found a 3 inch piece of plastic, what looked to be a plastic bucket lip in a bag of pellets yesterday. Some have found pieces of bag. I had a rodent get screwed into the works that came in with the corn and somehow got past my screening.

 

[jzm2cc]

Pop off top panel on rear of stove and watch auger turn. Bearing on auger link should fully contact C shape cam that causes feed plate to move in and out. This action allows pellets to drop into auger. On my stove the bearing wasn't contacting the cam throughout rotation so minimal pellets were being allowed past feed plate. Took a while to notice this and i was trying different ESP's, curcuit boards, electrical outlets, pellet lengths, first
.

 

[rickwai]

watch auger turn. it should turn 1 time every 15 seconds

 

[PennPellet]

I have a feeling this may be the issue. I would have to empty the hopper to do this, right?

I just checked, the roller only touches the C shaped cam initially, then again at the end of the motion. They stop touching for the majority of the upper rotation. Should they be touching the entire rotation? If they should be, what would cause this to happen?

 

[Bioburner]

The movement of the lower arm of the slide actuator is only about half an inch and the roller does not touch that entire cam but a very small portion of the top and bottom.

 

[smwilliamson]

I've seen instances where there was massive jam in the system and the cam roller bends the slave arm and caused a low feed issue. I had the end the slave arm back and thenproblem went away

 

[Bioburner]

I suggested something plugging the works this AM

 

[PennPellet]

So the pellet stove is working again. I honestly can't say 100% what the problem was in the first place or why its working again.

To review, I was a having a problem with low flame and slow/limited pellet feeding.

1) I initially did a thorough cleaning of the stove. The fines box was pretty full of dust and pellets. I remember the last bag of pellets I had poured in was especially dusty / had weird pellets -- they seemed extra fat/powdery. Just unusually shaped. i also saw a few clumps of pellets. I'm not sure if this has anything to do with it...

2) I tried the stove after cleaning -- same problem.

3) next I cleaned the ESP --- tried it again, still not working.

4) I decided to watch the auger cam --- apparently it was working correctly. While watching the unit working, I decided to jiggle the C shaped cam -- when it would lift, I would lift it a little extra. After watching this a bit, I had no idea what was going on in the stove. When I took a look at the flame it was back to normal.

5) I've shut the stove down and restarted it a few times now...there seems to be no problem anymore...

6) I still have to clean out the exhaust from the outside --- I'll save that for next weekend.

7) If the problem arises again I will post again.

8) ultimately, the stove was a bit on the dirty side --- if anything, i'll do deep cleanings a bit more frequently now...

9) Thanks to everyone for their support and help

PS. I called the closest dealer to have a look -- they wanted to clean the stove for $300. They said that in their experience these machines just need a nice cleaning. They wouldn't come out to just do a diagnostic (I understand their perspective, but still...) --- Ultimately I'm glad I could avoid shelling out $300+ to a dealer...

 

[Bioburner]

Clean it again, check
$300, sounds like the health medication rate of increase

 

[jzm2cc]

Regarding the roller touching the stamped steel cam. As long as cam touches the middle of roller it should be fine. Mine was bent so the cam contacted the bolt that mounts the roller thus reducing the stroke length of the feeder plate. Doesn't sound like you have this issue.

 

[PennPellet]

Regarding the roller touching the stamped steel cam. As long as cam touches the middle of roller it should be fine. Mine was bent so the cam contacted the bolt that mounts the roller thus reducing the stroke length of the feeder plate. Doesn't sound like you have this issue.

Agreed, but it was definitely worth checking.

thanks for the help!

 

[ajbass]

Hi, I have two 2011 P43's and had the same issue. set feed rate to 6 and still wasn't feeding enough. cleaned and checked everything. Replaced door gaskets, esp, exhaust fan (noisy) and tried a back up control board. Not one thing cleared it and one day it started dumping over pellets and moved feed rate back to 3 and stove is running as good as new. Now, the 2nd stove is still running on max feed and I did all the same things as I did on my 1st stove???

While the stove is running I can move the auger arm (when it hits idle cycle) to open and close and here more pellets feed. After doing this I get a normal burn. I have totally clean the feeder chute and fine box. I do need to get a gauge to measure the draft.

 

[hinkle]

I'm still in the process of searching, but does anyone have a link to how the auger should perform?

I'm following the steps the OP did, thorough cleaning including the fines box, ESP (next). When I had the back off I checked that everything was spinning, which it is, but still have a slow feed.