Burn Pot deposits making ignition difficult or fail

[BitTwiddler]

What is your experience with carbon buildup on the burn pot grate?

I bought a floor-model (6900 hours on the clock) Harman Absolute43 this month. Their technician cleaned it before I picked it up but it quickly had difficulty igniting the pellets. He came out, looked it over, did another cleaning, and replaced the igniter. It took a while igniting for him, and that night it had further problems. Since then it has had long ignition times (up to 22 minutes - the technician said it should only take 5-7 minutes) or failed to ignite altogether. I finally got tired of just scraping the burn pot and took out the burn grate (the plate on the bottom with lots of round holes in it) and cleaned it with a file in my garage until it was all metal. THAT FIXED IT.

It seems that an arc of carbon forms and serves as insulation, reducing the heat that comes from the igniter to the fuel during startup (see photos - the plate should be flat except for the fin). The scraper provided to me was dull and so was not sufficient to remove this carbon. Taking the grate out and filing it did the trick, but was a fair amount of work and mess to perform every day. Subsequenly, I took an old metal file and ground the end to be like a chisel, which does a nice job of chipping the carbon off, and it is hard enough to stay sharp quite a while, unlike the mild steel of the original included scraper.

Am I unique with this problem, thus requiring a different non-standard solution?

 

[jerrieric]

I have a revalli and clean it every five days. Hardly any buildup in the burn pot but I scrape it every time with a 1in chisel. I burn the cheap pellets in the box stores that haven't given me any real klinkers and I've been using these type pellets for about 10 years now. Now when I had my Enviro Mini I did get clinkers burning the same type of pellets. So I don't know what the real issue is, is it with the efficiency of how the pellets are burning or is it the quality of pellet? If it's the quality of pellets The Big Box store pellets don't seem to give me an issue.

 

[JR52]

I have a slightly different burn pot grate with the Absolute 63, but I am often fighting the carbon deposit issue. Unlike you, I can't remove the grate without removing the entire burn pot. I hit it weekly with a gasket scraper and it normally gets it pretty good.

 

[zrock]

Different stove but get the same thing in my burn pot... if I scraped it quickly daily it was never a issue. But this year I'm lazy and only do it every few weeks and takes a bit of effort to clean

Sent from my SM-G950W using Tapatalk

 

[BitTwiddler]

I have a revalli and clean it every five days. Hardly any buildup in the burn pot but I scrape it every time with a 1in chisel. I burn the cheap pellets in the box stores that haven't given me any real klinkers and I've been using these type pellets for about 10 years now. Now when I had my Enviro Mini I did get clinkers burning the same type of pellets. So I don't know what the real issue is, is it with the efficiency of how the pellets are burning or is it the quality of pellet? If it's the quality of pellets The Big Box store pellets don't seem to give me an issue.

These claim to be "premium" pellets. I have seen no clinkers and it seems to burn nicely. Since I discovered the cause of the problem, I have not tried to go more than a day because (1) the carbon buildup is significant after just a day and I don't want ignition problems in the middle of the night and (2) The ground-down file I'm using makes quick work of the carbon buildup.
I just thought that buying a high-end stove like this would not result in more work and mess than my old woodstove I had in Dallas (beside the actual cutting, splitting and stacking of the wood, which compensated for the cost of pellets which are already cut, split and stacked).

 

[BitTwiddler]

...every few weeks Sent from my SM-G950W using Tapatalk

I think if I tried more than a very few days my stove wouldn't ignite at all.

 

[BitTwiddler]

I have a slightly different burn pot grate with the Absolute 63, but I am often fighting the carbon deposit issue. Unlike you, I can't remove the grate without removing the entire burn pot. I hit it weekly with a gasket scraper and it normally gets it pretty good.

Then my ground-down file would be just what you need. And I think that the slightly seerated edge provided by the file's teeth helps it break through the carbon more easily.

 

[Mt Bob]

There is nothing wrong with your stove,and probably nothing wrong with your pellets.the stove was not properly maintained,nor properly cleaned.That is what is commonly known as "the harman speed bump".I would have no faith in that technician.That should be cleaned/scraped on a regular basis,page 13 of your manual.

 

[GeHmTS]

Your not unique to this problem and it is something people run into from time to time. What has worked for me is to use a large screwdriver with a bent tip. You have to create a preventive maintenance schedule that works for your stove.

https://www.hearth.com/talk/threads/harman-scraping-tools.126770/#post-1704177

I sharpen the tip every deep clean with a sharpening stone to keep it sharp.
https://www.amazon.com/dp/B00Y75X07Y/?tag=hearthamazon-20

I scrape daily to remove all carbon buildup on the surface. Every other week, I also put a drill bit in between all the holes to remove any carbon build up where the oxygen is flowing. I turn the drill bit by hand. My stove fires up reliably without any issue.

 

[mikkeeh]

My p43 burns basically non stop from November to March. Going on year 8. Never
had an issue with carbon buildup. Do a quick scrape of the burn pot once a day.

 

[Connecticut Yankee]

These claim to be "premium" pellets. . . .

"Premium" is marketing-speak for "more expensive."