Harman P38 Pulverizing Pellets - Help Please!

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here

sdheath

Member
Nov 28, 2019
8
Connecticut
I'm going nuts trying to figure out what the problem is here, and after extensive searching I haven't found anything online that looks like anyone else has had this issue. But if the answer is out there, I'm sure this is the place to find it!

The background: I bought this P38 new about 13 years ago and it has been my primary heat source for most of the time since. This fall I upgraded to the new 3-knob control board and the stove worked great for a few weeks. One day it stopped running and gave me the six blinking lights. I checked for obstructions, cleaned the ESP (which was new with the control board kit) and did the usual cleaning tasks including checking and emptying the fines box. I restarted it and it was OK for a few days then it quit again. I checked everything again and noticed that there was sawdust instead of pellets coming out of the auger. I pulled out the auger and it was packed with sawdust. Assuming this was some fines buildup from 13 winters of full-time use I cleaned that and tried again. The stove ran fine for a week then on a warm day I shut it down. I restarted it the next evening, and woke up to find it had quit again. I checked the auger and it was packed with fines again.

Three days ago after pulling the sawdust-packed auger, I reached and poked up inside the auger tube to the passage where the pellets fall from the feeder to the auger. There was some sawdust packed up in there too, so using my fingers and assorted tools I poked and scraped until I was sure the path between the feed tray and the auger tube was totally clean. Feeling confident this time, I fired up the stove and it ran fine until I shut it down yesterday when we had a houseful of family over for Thanksgiving. At the end of the day I cleaned the burn pot to find the familiar sight of sawdust. The auger was packed with fines again.

To summarize:
- my auger fills with sawdust in a matter of days, and the pattern seems to indicate it could be happening, or at least worsening, during shutdown.
- I have thoroughly cleaned the stove including burn pot, hopper, feed mechanism, fines box, auger and auger tube, intake, circulation and exhaust.
- The feed mechanism pushes pellets down to the hopper just fine when I watch it run, and it moves smoothly when I move it manually. No apparent obstructions.
- I have tried three brands of pellets from three different sources, all being premium grade pellets. I am primarily using CleanFire Pacific, which have served me well for six or seven years.
- I have confirmed that the auger motor is running when it is supposed to.

I'm a hard-core DIYer, so calling in a professional will be my last resort but I'm getting there quickly. But before I do that I'm hoping I can get some help from the Hearth community. So what's my next move? Thanks in advance for your suggestions.
 
The first thing I would try is 2 or 3 bags of a different brand pellets. Maybe the pellets you have got damp or there was something wrong with the batch.
 
The first thing I would try is 2 or 3 bags of a different brand pellets. Maybe the pellets you have got damp or there was something wrong with the batch.
Yeah I thought so too. I have tried three brands of pellets from three different sources, all being premium grade pellets. I feel comfortable at this point saying the pellets aren't the issue.
 
  • Like
Reactions: jackman
Pull the auger and check it may need a new one after so many Years
 
Are the pellets making that familiar tinkling sound as they drop? If not, that may be a clue. I don't have the exact same stove but maybe there's something stuck on the feed slider plate that's buggering the pellets.
 
  • Like
Reactions: sdheath
Are the pellets making that familiar tinkling sound as they drop? If not, that may be a clue. I don't have the exact same stove but maybe there's something stuck on the feed slider plate that's buggering the pellets.
When everything is clean I clearly hear the tink-tink of dropping pellets. But after a while it stops, presumably as the auger starts to fill with dust.
 
maybe there's something stuck on the feed slider plate that's buggering the pellets.

I pulled the slider plate out. The top had a light coating of pellet residue. The bottom had a small but distinct ridge of buildup. I gave both a good cleaning, hopefully that makes a difference! Thanks for the suggestion.
[Hearth.com] Harman P38 Pulverizing Pellets - Help Please!
[Hearth.com] Harman P38 Pulverizing Pellets - Help Please!
 
Thanks for the update. Do let us know if that cured it.
 
Yeah I thought so too. I have tried three brands of pellets from three different sources, all being premium grade pellets. I feel comfortable at this point saying the pellets aren't the issue.
everyone seems to call their pellets premium... Our local stores sell a Platinum pellet and its the worst pellet iv used. Was so many fines in it that it was packing up my auger same as you... The walmart brand of pellets this year is better..LOL
 
*Update*
Last night before bed I pulled the burning pellets forward in the pot and peeked at the auger. It was pushing whole pellets forward with no sign of sawdust! So I left just enough pellets in the hopper for it to run out before dawn. When I got up I cleaned the burn pot and ran it in test mode to see whole pellets still coming from the auger. I don't know if it was cleaning the slider plate, or just resetting the auger one more time, but so far I'm pleased with how things are going.
 
PROBLEM SOLVED!
Yes, I know it's been almost a year, but at least this time I'm sure it's fixed. A few days after my 11/30/19 post, the pellet dust came back. This time as I pulled the auger out, I took a close look at it and immediately realized what the problem was. The weld holding the front end of the auger to the shaft had busted, and the auger had compressed by at least an inch. So from the back of the auger to the front, the space between each rotation got progressively smaller thus crushing the pellets. I ordered a new auger and popped it in, and the rest of the heating season went flawlessly.

Sorry it took so long for me to post this update, but at least it is documented now and will hopefully help someone else in the future.

Old auger on left, new one on right:
[Hearth.com] Harman P38 Pulverizing Pellets - Help Please!
 
Thanks for the update and the pic