Harman P61A smoke in hopper

[mikesj]

Hi all,

I've been burning a Harman P-61A for 4 or 5 years now. All sorts of little problems, a fair portion of which were user error related. This is a new one to me, though.

This AM I opened the hopper to fill the stove and there was smoke in the hopper. Not enough to set off the alarms, but enough to smell up the room. I noticed this one other time a couple of weeks ago, but discounted it- now I'm wondering if I've got a bigger problem. The hopper was empty, but there was a small fire burning in the burnpot.

Any ideas/suggestions? (BTW, my dealer is an hour away and of no help).

Thanks!

Mike

 

[Delta-T]

pull out the slide plate in the feeder box and see if there's any buildup on it.....then report back. its very very very rare to see the "gummy feeder" on the P61 but it can happen. Do you have OAK?

 

[DAKSY]

If the hopper was empty, then it's a good bet some or all of the auger was empty as well.
It's conceivable that some smoke could work it's way back thru the auger & when the slider plate opens,
some could make it into the hopper...
After all, it's a positive pressure system...
With a full auger, I'd say the chances of that occurring are slim to none.

 

[Delta-T]

the P61 is actually a negative pressure machine, but the hopper is a static negative pressure environment...so there is a chance that smoke can get "sucked" into the hopper. I'd still check the slide plate to see if its dirty.

 

[mikesj]

Sorry- forgot to mention no OAK

 

[Bxpellet]

My Advance had this problem there is a modification from Harman that corrected this, The new stoves had this done from the factory, My dealer is also an hour away, he faxed over the memo with directions and I had him on the phone when I did it. There are some people on this forum that got new stoves. Call them and ask about it.

 

[mikesj]

Even if my dealer would return my call, I'm sure that I wouldn't get a new stove out of this- I've been running it for 4 years now without this being a noticeable problem. I did a full shut down today, scraped the burnpot and cleaned out the auto ignite cleanout under the pot. I then re-fired it up with just a few pellets in it to see if I could reproduce the smoke. As I type, the flames are dying out and no smoke smell to speak of in the hopper.

My thoughts are that the smoke problem is due to one of a couple of things:

1) New pellets. The ones I'm burning now don't seem to be of the same quality as many others I've burned in the past- they seem to make a considerable amount of ash in burnpot- I'm burning through a ton of "Wood Pellet Co" from somewhere in PA. They seem to have a decent amount of fines in them for "Premium" pellets. (I've got 5 tons of Lignetics backing me up

2) Dirty burnpot + dirty pellets. I've only burned a few bags, but I haven't been regularly scraping the pot out. I did have a decent amount of crud in the pot.

3) Some sort of crazy malfunction that will cause the stove to explode in a WMD inspired blaze of glory.

Right now, things seem to be settled down. Hopefully the thorough burnpot cleanout is all that's required. Even if the burnpot fire would somehow work its way back through the auger to the hopper, it seems very unlikely to me that a sealed hopper could support a serious conflagration.

Thanks for the responses - any other thoughts would be greatly appreciated.

 

[freebird77]

I had a similar problem with my P61. I have been told that certain year models had poor welding and smoke was getting into the hopper. Mine didnt do it all the time, and only noticed it when the hopper was partially full. The first time the dealer tech came out,he checked the slide plate and it was gummed up some. Cleaned it and took pictures of it for Harman. I stil had intermittent smoke over the next heating season. The man came out again after approval from Harman, and replaced the burnpot, slider plate, and pellet feeder, if I remember correctly, even the hopper. I didnt have any more problems that winter, but there wasnt a lot of heating time left by then, so we will see. Dont know if yours is still under warrenty or not, but smoke in the hopper is surley not normal. There are some others here that have had problems, I believe the Advance, or was it the Accentra? have been noted for that. I know Toastirini went through similar issues. Let us know what you find out.

 

[freebird77]

https://www.hearth.com/talk/threads/15632/

 

[mikesj]

Ok- I pulled the slide plate this evening and it looked ok. Definitely not scorched or gummy. Then, when I put the stove in test mode, the auger pushed out unburned pellets which tells me that I don't have burning going back through the auger. I'm thinking that the smoke was due to poor airflow due to a cruddy burnpot. We shall see.

Thanks for the posts

 

[stoveguy2esw]

add an oak , the negative pressure environment is the house itself, without the oak you are pulling a minimum of 50 cfm out of the house, if the house doesnt let that back in it builds negative pressure which with the help of a leak in the feed system or hopper draws smoke into the hopper.

oak will cure the problem , but i'd suggest looking at gasketing and seals in th ehopper and feed system for a leak which is allowing this to happen under negative pressure from the house

 

[toastyinri]

I had a similar problem with my P61. I have been told that certain year models had poor welding and smoke was getting into the hopper. Mine didnt do it all the time, and only noticed it when the hopper was partially full. The first time the dealer tech came out,he checked the slide plate and it was gummed up some. Cleaned it and took pictures of it for Harman. I stil had intermittent smoke over the next heating season. The man came out again after approval from Harman, and replaced the burnpot, slider plate, and pellet feeder, if I remember correctly, even the hopper. I didnt have any more problems that winter, but there wasnt a lot of heating time left by then, so we will see. Dont know if yours is still under warrenty or not, but smoke in the hopper is surley not normal. There are some others here that have had problems, I believe the Advance, or was it the Accentra? have been noted for that. I know Toastirini went through similar issues. Let us know what you find out.

Ok, I'll check in on this one. I had two Harman Advance replacement stoves because of the smoke in hopper issue. Gummy slide plate is an indicator . ( I had posted pictures of the slide plate either in 2007 or 2008. Harman sent out the 3rd stove with all the "fixes". Burned it all last season with no issues using the same pellets (Fireside Ultras) with no problems. Fixes seemed to eliminate pot clinkers (no more chipping and chiseling out buildup in burnpot) This year I'm burning Appling County (yes, I know, they've gotten horrible reviews). Have burned 5 bags so far with no issues,,,but real test is when the constant cold below 35 degrees kicks in. Good airflow seems to be the factor that the fixes corrected, but I say that only from what I've noticed after having 3 stoves. I'm a set it and forget it burner....rarely fiddle with it. Keep it clean,(this includes keeping fins on fans free of dust,,have pets, must vacuum) have always had OAK. The biggest thing I've noticed since getting the stove with fixes is less full cleaning. Do a full breakdown once a month, a couple of sweeps of burn pot daily, and a quick brush swiping of back plates, sides and top ledge, once a week. Full clean also includes going outside and sticking my vent brush down the pipes and emptying tee. Venting as per Harman recommendation with horizontal inside the house. I think I covered the bases, any questions, feel free to ask

 

[toastyinri]

Ok- I pulled the slide plate this evening and it looked ok. Definitely not scorched or gummy. Then, when I put the stove in test mode, the auger pushed out unburned pellets which tells me that I don't have burning going back through the auger. I'm thinking that the smoke was due to poor airflow due to a cruddy burnpot. We shall see.

Thanks for the posts

Keep those airholes in the burn pot clean...paper clip does the job nicely. Be aware that gummy slide plate doesn't happen overnight, it takes time for the buildup to happen. In my mind the only way to really know that you haven't had back burn is to remove the auger and check the tube & auger for crusty coal like buildup.

 

[freebird77]

Toasti, Ive never cleaned the oak vent. Do you actually find anything in there when you brush it out?

 

[toastyinri]

Toasti, Ive never cleaned the oak vent. Do you actually find anything in there when you brush it out?

I clean the air intake cap on the outside of the house,,, sometmes I'll find a small leaf that's been sucked up,,,mostly a web or two. When I turn on my Harman I check it by putting my hand near the cap to check for air draw. Never found anything inside the air intake tube itself, but I stick the end of my vacuum in it once a year just in case something might have crawled in.