Large smoke cloud expelling outside from Harman PB105

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dmedeiros517

New Member
Aug 26, 2022
7
CT
Hi everyone, I'm looking for some help as the pellet stove store near me has been no help so far.

We moved into a house which has a Harman PB105 and have had nothing but issues with it. Initially it would cause a large explosion while trying to reignite. We would find the entire basement filled with smoke, the cap on the exhaust pipe blown off with ashes every where and a huge cloud of white smoke filling our yard making the neighbors think our house was burning down.

We initially had the thing professionally cleaned top to bottom and were assured it would be all set, but it kept doing it. We then tried taping all the seems on the exhaust pipe with aluminum tape for potential air leaks. This did help decrease the amount of smoke constantly in the basement but that was it. We then replaced the gasket on the bottom ash door. Lastly we had the company come back out to take another look and they replaced the igniter saying they should've caught it the first time but this should fix all our issues.

I called the company back saying my initial concern of massive clouds of smoke still exists and all I was told was they can't say what is too much smoke or not but all stoves expell smoke. I understand this is my first pellet stove I've ever owned but I'm pretty positive if everyone's house looked like it was on fire every time the thing auto ignites, I don't know why anyone would every buy one.

Does anyone have any suggestions as to why it could still be smoking like this?
 

Former Farmer

Minister of Fire
Apr 12, 2008
653
NE Wisconsin
Does it smoke only upon startup or all of the time? This will make a difference on where to start looking.

It is normal to have some smoke at startup, not a huge amount. After the fire gets going, you shouldn't see hardly any smoke from the exhaust vent cap.
 
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dmedeiros517

New Member
Aug 26, 2022
7
CT
Does it smoke only upon startup or all of the time? This will make a difference on where to start looking.

It is normal to have some smoke at startup, not a huge amount. After the fire gets going, you shouldn't see hardly any smoke from the exhaust vent cap.
Only upon startup each time then after a couple minutes it fades back to barely anything visible
 

Former Farmer

Minister of Fire
Apr 12, 2008
653
NE Wisconsin
Do you have the finned igniter or the pressure igniter?

If you have the finned one, does your burnpot have a bubble forming over the location of where the igniter sits below it?

You stated that you had the unit cleaned. Did they clean the fines area on the feed auger assembly? Did they remove the combustion fan and clean the fins on it as well as that area of the boiler?
 

Washed-Up

Minister of Fire
Nov 5, 2011
1,034
Kananaskis,Alberta, Canada
Photos of your burnpot(empty) would help…sounds like the holes in the burnpot might be covered in carbon, inhibiting proper ignition, or an intake air issue/blockage.
 
Last edited:

dmedeiros517

New Member
Aug 26, 2022
7
CT
Do you have the finned igniter or the pressure igniter?

If you have the finned one, does your burnpot have a bubble forming over the location of where the igniter sits below it?

You stated that you had the unit cleaned. Did they clean the fines area on the feed auger assembly? Did they remove the combustion fan and clean the fins on it as well as that area of the boiler?
We used to have the finned igniter but they replaced it with the pressure igniter this week. And yes that cleaned all those areas as far as I am aware.
 

Dataman

Minister of Fire
Sep 10, 2018
1,120
Newport, Wa
Run in Manual so it does not go out. I have Harmon XXV and it also fills with smoke and goes poof on start up. No Leaks at all.
 

Former Farmer

Minister of Fire
Apr 12, 2008
653
NE Wisconsin
Read through this thread.

 
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zrock

Minister of Fire
Dec 2, 2017
1,277
bc
To me that would indicate that your exhaust / or exhaust fan is plugged not moving enough air. When i notice mine is building up to much smoke in the chamber on start up its time for me to pull the fan and clean the blades and give the pipes a good clean. Does not seem to be getting enough air flow and when it finally ignites it lights the smoke off to..
 
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dmedeiros517

New Member
Aug 26, 2022
7
CT
Photos of your burnpot(empty) would help…sounds like the holes in the burnpot might be covered in carbon, inhibiting proper ignition, or an intake air issue/blockage.
20220828_210830.jpg

Just fully cleaned the whole unit tonight again. This is what the burnpot looks like. I apologize as I'm still new to this but I couldn't tell you the first thing about if anything looks wrong with this burnpot or not. The only thing I noticed was possible breakage further down inside but I can't see how that small area would affect the function. I also do not see anything that looks like a bubble like other people have mentioned they had unless I'm not clear what the bubble looks like. I also did not see any holes blocked.
 

dmedeiros517

New Member
Aug 26, 2022
7
CT
To me that would indicate that your exhaust / or exhaust fan is plugged not moving enough air. When i notice mine is building up to much smoke in the chamber on start up its time for me to pull the fan and clean the blades and give the pipes a good clean. Does not seem to be getting enough air flow and when it finally ignites it lights the smoke off to..
How often should the exhaust pipe be cleaned? The fan and pipe were cleaned by a company not that long ago. I cleaned the exhaust fan tonight while cleaning everything else but it didn't seem to have too much build up on it.
 

zrock

Minister of Fire
Dec 2, 2017
1,277
bc
i can see part of the problem in that picture.. Your burn pot needs a good scraping their is lots of buildup around the edges. This is from the minerals in the pellets and makes a hart steel like crust in the pot.. I have to use a gasket scraper on mine to get rid of it.. Some pellets are worse than others i have tried a few different brands locally and found some that leave next to nothing..

Also looks like your burn pot is cracked along the bottom and left side... that may just be the build up as well
 
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Mr._Graybeard

Feeling the Heat
Apr 27, 2012
411
Southeast Wisconsin
The pressure igniter should result in a big improvement in ignition. The burn pot in the pic looks like it still has a fair amount of carbon in it. I like to clean mine with a paint scraper. Sometimes you really have to lean into it to chip off that carbon scale.
A dirty exhaust fan can hinder ignition, resulting in explosive startups. Make sure the backing plate behind the fan blades is scraped clean. My boiler runs like a charm as long as the fan is clean.
I run a brush through the flue pipes maybe twice a season. But I clean the fan area every six weeks or so. I heat nearly 100% with the boiler; last season I burned about 6 1/2 tons of pellets. I'm coming up on my 10th season with the PB105.
I use zoned thermostats in my house, and have found that running the boiler on manual will cause it to overheat, Even if you have a dump zone, the boiler will shut down and register an error code.
Another thing to keep in mind is that you want to keep the boiler temp above 140 degrees. If it drops below, you'll get condensation which produces creosote. You definitely do not want creosote in your boiler.
 

dmedeiros517

New Member
Aug 26, 2022
7
CT
i can see part of the problem in that picture.. Your burn pot needs a good scraping their is lots of buildup around the edges. This is from the minerals in the pellets and makes a hart steel like crust in the pot.. I have to use a gasket scraper on mine to get rid of it.. Some pellets are worse than others i have tried a few different brands locally and found some that leave next to nothing..

Also looks like your burn pot is cracked along the bottom and left side... that may just be the build up as well
That picture was unfortunately after some serious scraping with a metal chisel. Are you saying more is caked on that needs to be scraped off for better function even though all the holes at the top are clear and open?

What pellets have you found to work the best? The last few tons we used were the Vermont soft wood pellets but that's when we had a lot of issues and a lot of ash build up. We are currently trying a premium hardwood from Tractor Supply that was supposed to be really good. Thanks for all your help
 

zrock

Minister of Fire
Dec 2, 2017
1,277
bc
Yes their is still alot of build up in their.. I have had to use a hammer and my scraper before to get it out same as one of the comments above... The pot should be cleaned weekly
 
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Washed-Up

Minister of Fire
Nov 5, 2011
1,034
Kananaskis,Alberta, Canada
When I get a bad batch of pellets and big carbon build up, I’ll use a dremel with the brass brushes to get back to bare metal
 

Mr._Graybeard

Feeling the Heat
Apr 27, 2012
411
Southeast Wisconsin
Harman pots develop a "speed bump" of carbon buildup just behind the bottom row of holes. I think I see that accumulation in the pic. I think you'll get that to some extent no matter which brand of pellets you use
 

Former Farmer

Minister of Fire
Apr 12, 2008
653
NE Wisconsin
You should also make sure that ALL of the holes in the burn pot are clear. The holes at the bottom of the burn pot are very important for startup.
 

mtnbiker727

Feeling the Heat
Mar 11, 2019
281
PA
My P68 throws a lot of gray/white smoke while it is igniting, but after the smoke in the window clears, the smoke outside is clear as well.

Take a scraper of some kind and scrape the sides of the burnpot down, and the bottom. The whole thing should be smooth all the way down to the auger.

The book tells you to scrape the sides and bottom all the way down every day. I have figured out I can go every few days... but if I get lazy and only do it once a week, then it's more work to scrape it.

Be careful poking those holes, because your igniter is under there and can be damaged.
 
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