Harmon P61 plastic odor

[Gymshorts]

I've been burning Somerset premium grade hardwood pellets in my Harmon from the time it was new 2 years ago and I always vacuum and clean the entire inside of the stove, exhaust blower area and fan, and exhaust vent piping. Two days ago I started getting a real bad toxic odor that smelled like plastic burning and seemed to be coming from the back of the stove, around the vent piping. I shut it down and did a thorough cleaning/vacuuming and removed the vent pipe cleanout cap and knocked a bunch of what looked like dried creosote out. I cleaned it all out, cleaned the stove inside and turned it back on. After about an hour the odor returned so I had to shut it down again. I've never had any problem with this stove before but I noticed the bags of pellets seem to have more sawdust then usual in this last ton I've been burning.
What can cause this kind of odor from these stoves? If it's creosote, do I need to disassemble all of my vent piping to be sure it's 100% clean? Could I have some bad pellets?
My flame is burning good, not lazy so there doesn't seem to be a draft problem.
One other thing is that in the past month or so the stove has shut itself down a couple times for no apparent reason. All I do is vacuum, restart and all seems fine until now with the odor.

Thanks guys

 

[johneh]

As long as your stove is sealed properly you should get no
smell of burning . Did you get a smoke smell before this
smell started ? I would be checking the stove for a wire overheating
dirty blower motors overheating and a general inspection of the
wiring and outside of the fire box inside the panels. Maybe
something is sitting on the exhaust pipe inside the cabinet ?

 

[P51mustang]

Sounds like the smell could be the Somersets pellets. I seem to recall reading a thread on this site a week or so ago, probably in the pellet pricing or comparison thread, that the quality of somersets this year were not as good as years past. I think I recall one poster specifically mentioning that they have a plastic smell this year.....

Few other things: have you cleaned and checked the area around the combustion motor? Also, I assume you have cleaned your fine box area regularly? Have you cleaned out your chimney recently?

 

[Gymshorts]

Good advice guys. I usually burn the stove about a week or so in between cleaning. Cleaning being a thorough vacuum of the fire box and internal components including the top area along with removing the igniter cover and vacuuming. I have cleaned the exhaust motor fan blades and area all around that but usually just once per year.
I'm leaning heavily toward the Somerset pellets being a problem but I also have never disassembled and cleaned anything on the backside of the stove. Removing those panels will be something new but I do have some decent mechanical/electrical skills AND the manual.
No smoke odor before this problem started but I'll also do the dollar bill test of the door gasket if I can find one.
I ran the stove last night after cleaning and everything looked and worked great but the plastic odor came back after an hour with no other symptom. I went outside to check the vent and I had plenty of warm exhaust air venting but lots of plastic odor too.
Possible wire touching and possible pellet problem.

Thanks a ton and once I find the problem I'll post it.

Jim

 

[Lake Girl]

I would be checking the wiring; blowing out windings on blowers; cleaning the convection blower...

Smell of pellets can factor in there ... the Indeck pellets smell a bit swampy due to their mix of wood used. Makes me really appreciate the SPF mix of Spruce Pointes or LaCretes!

 

[Gymshorts]

Thank you.
In order to help narrow down this plastic odor, I took a small shovel full of my Somerset pellets out to the garage and burned them with a propane torch. No odor other then wood so now I'm convinced the problem is in the stove.
Motor winding or wiring that somehow moved onto the vent pipe is the direction I'm heading next.
I have never had the rear panels removed from this stove before so I'm sure I'll need to do some cleaning.

The strange thing about this is that the stove works great other then the plastic odor. I would think that if I had a motor or wiring problem something wouldn't work but I realize that isn't ALWAYS the case.

Now I'm battling a flu bug that has slowed this project.

Jim

 

[Lake Girl]

How high are you running the stove? I realize that curing should have been completed in two years but if you are running a hotter pellet at a higher heat level, paint may still off gas. Found that the first time I hit power level four on ours... second winter. Still would go searching the cabinet for the cause ... just remember to unplug before working in there!

 

[Gymshorts]

I know what you mean. Ours gave off a slight odor for a few days when it was new but it smelled more like a mild oil residue I assumed was normal. That cleared up and there hasn't been any odor at all until now. I haven't raised the temp on this or changed the settings much. I usually keep it set to a little above halfway.
Good advice on the unplugging. As a career electronics person I've learned that body parts are no match for live wiring. Ahhh, a few times.

Thank you

 

[Lake Girl]

Good advice on the unplugging. As a career electronics person I've learned that body parts are no match for live wiring. Ahhh, a few times.

Explains my extreme caution with electricity ... shocked myself as a kid

 

[Gymshorts]

That's a hard lesson to learn at a young age. I can sure understand how that can stay with you permanently.

 

[bags]

I have burned many tons of Somersets and never had a pellet issue. They have always been great pellets and very consistent across the years so I'd say you are right it is something other than the pellets especially after your field test burn.

Have you figured it out yet?

 

[Gymshorts]

I was going to wait until I actually put my hand on the smoking gun to post but, what I've discovered all makes sense now.
The problem turned out to not be the pellets OR the stove. The problem is, how can I put this so-as not to offend anyone, THE OWNER.
It all starts with my ash vac that came with various wands and a small swivel brush that I use for vacuuming the fire pot. After I cleaned the stove last time I took the entire ash vac out to the garage where it would get cleaned next. I loaded the stove hopper, started it and all seemed fine. I didn't notice my swivel brush was missing but it must have come off the wand down in the pellet feed area and when I started the stove the feed auger pulled it inside the stove and deposited what's left of it on the hot surfaces there.
The only symptom at that point was the stove tried to shut down automatically but didn't. It came back on, seemed to burn perfect but soon the plastic odor started.
I am sure that's what happened given all of the circumstances and I'm expecting a nice mess to clean once i find it.

 

[bags]

I was going to wait until I actually put my hand on the smoking gun to post but, what I've discovered all makes sense now.
The problem turned out to not be the pellets OR the stove. The problem is, how can I put this so-as not to offend anyone, THE OWNER.
It all starts with my ash vac that came with various wands and a small swivel brush that I use for vacuuming the fire pot. After I cleaned the stove last time I took the entire ash vac out to the garage where it would get cleaned next. I loaded the stove hopper, started it and all seemed fine. I didn't notice my swivel brush was missing but it must have come off the wand down in the pellet feed area and when I started the stove the feed auger pulled it inside the stove and deposited what's left of it on the hot surfaces there.
The only symptom at that point was the stove tried to shut down automatically but didn't. It came back on, seemed to burn perfect but soon the plastic odor started.
I am sure that's what happened given all of the circumstances and I'm expecting a nice mess to clean once i find it.

Crazy stuff like that happens around here frequently. LOL! Most are guilty of some stupid thing they did or missed and then figure it out and move on. that said, I bet you'll do an ash vac accessory inventory from here on out. Ha! I can be OCD about things like check, recheck, and check again. The kicker is after all my checks i have been known to still forget something or whatever. It happens. Luckily you just lost a wand, had to deal with the plastic smell, and a few head scratches wondering.... Some do stuff like that and it winds up costing them some money for a new part that was messed up because of an oversight. Like someone here tinkering with a brand new stove while it was plugged in and fried his control board. $300-$400 bucks later he figured out is was way easier to unplug it!

 

[Gymshorts]

I'm a firm believer in owning my errors because I have learned a lot that way. This is one of those and you are absolutely right about taking inventory.

So at this point I've checked to make sure the power cord is unplugged, 3 times, and have removed the stove rear panels to expose the motors. Other then a little dust, it's like new and I see nothing melted or hitting the hot exhaust vent. So now it looks like my missing ash vac brush didn't get lost through the pellet auger but probably came off when I was cleaning down around the ash pan area. That seems to make more sense because when I first removed the ash pan, the left side of it closest to the exhaust blower was totally covered with a thick, black crust that I'm guessing is what's left of my plastic brush. I scraped and cleaned everything in there but I'm sure that the vent piping has a certain amount of melted plastic left in it too. I'd need to completely uninstall the entire stove and pull it away from the wall in order to access the vent piping but I'm leaning toward reassembly now and just burning the rest of the debris out of it.
Any thoughts on that would be appreciated.
Now where's my ham sandwich?
Jim

 

[Gymshorts]

This will likely be my final post to this thread.
I went back in to the vent blower area and cleaned everything again but prior to this I wasn't aware I could access the main vent pipe through an opening above and to the right of the blower. I inserted only the metal wand of the ash vac and could hear a lot of debris being pulled in to the vac. Everything was checked and re-cleaned if needed and I installed all the rear panel covers making sure no wiring or anything was moved or had become a hazard.

One last check and I plugged the power cord back in. The hopper was full so I started the stove and it came on perfectly. I now have better draft then I'd seen since new so I waited for the plastic odor and there is none.

Thanks to everyone for your replies and suggestions. I have learned much more from this.

Jim

 

[bags]

This will likely be my final post to this thread.
I went back in to the vent blower area and cleaned everything again but prior to this I wasn't aware I could access the main vent pipe through an opening above and to the right of the blower. I inserted only the metal wand of the ash vac and could hear a lot of debris being pulled in to the vac. Everything was checked and re-cleaned if needed and I installed all the rear panel covers making sure no wiring or anything was moved or had become a hazard.

One last check and I plugged the power cord back in. The hopper was full so I started the stove and it came on perfectly. I now have better draft then I'd seen since new so I waited for the plastic odor and there is none.

Thanks to everyone for your replies and suggestions. I have learned much more from this.

Jim

Jim,
When you do your monthly cleaning use a paint brush when the stove is cool and dust off the exhaust fan blade etc; Anything you can hit back in there and vac it all out. This will help keep your exhaust venting clean and such. Just be careful not to damage your ESP probe which you can see if you look back into your exhaust.

You should be able to see the ESP if you direct vent easily but if your exhaust venting goes up then light will be slim. You can shine a flashlight in and see the ESP. It is important to also brush or dust off the ESP while cleaning for better performance. I do mine with a parts brush that can be had cheap at HF or elsewhere. It has a long handle and the bristles are at the end and round. Mine is 12 - 14 inches long. I think I paid about $1-$2 something for it. Actually there were two in the pack.

There are tons of cleaning tricks and tips here and the required "on the fly" tools etc; to do so are described. Just use the search bar here and plug in (cleaning a harman) , (cleaning tools for the firebox), (cleaning the ESP probe), etc; or any variation you need answers for.

I would say you figured out what happened but you are not one of the worst. There have been some pretty amazing things that have wound up in pellet stoves here that have caused issues. Toys, bats, birds, mice, foreign objects in pellet bags, etc; During the one ton or monthly clean it is good to do a complete look over in and around your entire set up. Dust bunnies and such can collect and so forth. I pop both rear shields and vac as well and wipe stuff off. Not totally needed but neither is waxing a car each time you hose it off. But the car does need waxed as needed to maintain and nice ride and help the paint out for longevity. Good Luck.

 

[Gymshorts]

Bags,
You must be good at this because now you're reading my mind. It occurred to me "after" I vacuumed out the vent pipe that the ESP probe is located there and I remembered reading in the manual about being careful not to damage it. Well, the stove is working perfect after running all night so I must have gotten lucky again. Also, sitting here last night with outdoor temps at 8 degrees and my house at 66 degrees really made me appreciate this stove much more and figured it was probably time to start being a little nicer to it and look for some new cleaning tools.
I picked up a couple short handled wire brushes with scrapers that work great for the larger areas along the inside walls and flat surfaces but still need something better then the Harmon tool for cleaning the heat exchanger.
Your advice about more of these kinds of tools is very helpful and I'll follow through with my searching.

One big thing I'll do today is document all of this and start my own maintenance folder with notes on "do's and dont's". I'll never remember this stuff by next heating season and if there's anything that really bothers me a lot it's making the same mistakes over again. Once is plenty.

I watched the video on replacing the vent motor and couldn't believe the possible chore of having to cut the motor shaft and destroy the fan blade in the process. I realize the set screw for the fan must come out for a smooth job but those screws don't always cooperate. From my perspective it begs the question "does Harmon use Loctite or some other adhesive on those set screws"?

Jim

 

[Gymshorts]

Forgot to mention, my vent system IS direct vent. My stove is installed in a very dry and partially finished walkout basement that I plan to finish in a year or so. My intention was never to use pellet heat as my only heat source but more as a supplement to the forced air propane fired furnace.
After my first year of burning pellets it turned out that there were additional benefits that were not considered that we can't hardly live without now. Because the stove is located under the center part of the house, the floors upstairs stay warm all winter. That is very nice. The basement, typically the coldest room in any house, is now quite usable as living space. Also, without any blower ducting at all, heat rises up the stairwell and heats the entire house without drafty air blowing around like the propane furnace. I installed a small (30 in.) ceiling fan above the stairwell to help in pulling hot air up a little better and it works great set to the lowest speed. Last but certainly not least, my propane company doesn't like me. It's like getting the lottery bureau mad at you for winning too much. It really breaks my heart.

As for surprises in and around the stove? I can imagine what some people could find especially those with kids and pets. Our kids are all adults living on their own but when they come to visit with Grandkids, I shut down the stove. Also, our pets are all of the outside wild type like Deer, Turkey and such so other then an occasional spider or little bug getting in the stove it stays real clean. I have nobody to blame for putting stuff in there that shouldn't be. I did it, it's me, the mirror is talking to you again. Still gotta have fun.

Jim

 

[FirepotPete]

>I did it, it's me, the mirror is talking to you again. Still gotta have fun.<

It's important for all of us to share information, embarrassing as it might be at times. Little things that help each other, when you contribute it helps everyone here. A check list is a good idea and can be edited over the years.

My biggest boo-boo so far was leaving my shop-vac hose open after moving a couple of tons of corn. I had everything else sealed up after moving the corn so critters wouldn't get in, barrels, totes, secondary tank, everything, or so I though. Spring came and I went to change over the shop-vac for summer use and when I opened it up I could see that Mickey and Minny had been feasting on the corn dust, bag and HEPA filter over winter!

I've been told I'm a pretty sharp person but when rodents outwit you, you need to reevaluate just how sharp you are!

 

[Gymshorts]

I wouldn't feel too bad about mice outsmarting you. They can be very resourceful little critters, that's for sure.
The hardwood pellets I buy get stored on their skids in my garage and I was very concerned about mice getting interested in those. I trap an occasional mouse out there but they've never gotten into the pellets I'm real happy to say.
Having a forum like this is a real good thing and if I can contribute I'll always do so regardless of anything dumb I may have done. I'm not shy about it but if I've done the work to figure out a problem I didn't cause, I'm not shy about that too. It's all about learning and I'm sure I'll be back here again to ask questions and to contribute with hopes that it helps somebody.

Thanks for your reply.

 

[bags]

There are many here with much more knowledge and better than myself. I've learn about everything here from others helping and a boat load of research and reading. That and a rework of a used PC45 I did in which I was guided along very well by Bioburner here. Doing that gave me some great experience and much more knowledge of these stoves.

As for the set screw there is no Loctite applied from the factory. What happens is it seizes up over time from rust, corrosion, excessive heat, etc; Really it is not a big deal if it does just a bit more work getting it all out for replacement. Then you just buy a new fan blade for around $15 or so the last I saw or heard.

One thing you can do if you stove is newer and you can get the set screw spinning is to take it out and remove the fan blade for a good clean. Then use anti-seize on the shaft and set screw. i have done this and continue it about every time I do a big deep clean. It has worked well and the set screw always comes out easily. I decided to do this just so things are easier when and if I need to replace the exhaust blower motor.

That said the same set screw in my PC45 is seized. I've tried penetrating oil soaking and all kinds of stuff. No luck so that'll be a cut off job when it goes. Anti-seize is wonderful junk. it is cheap but can be very messy even working with small amounts so have rags around if you do it. I used it on a bunch of stuff on one of my motorcycles and I looked like the Tin Man all silvered out when I was done. On this particular bike it was hit extensively with either Loctite or anti-seize depending on which bolt, screw, etc. I'm sold on both.

 

[Gymshorts]

Bags,
I can appreciate all of what you say very much and to the point of where I'm doing a lot of research right now to get information in the direction of my own expertise of over 40 years that could be applied to pellet stoves and hopefully be a big help to people on this forum and others. I'll see where it goes.

I was pretty sure there was no Loctite on the fan set screw but thought I'd ask. Considering the high heat, dirt and time I can totally understand how that thing can seize up on its own. Your advice to remove it on mine while I may still have the chance is good. I'm only a week into a burn from the last major cleanup but in the meantime I'll pickup some anti-seize compound and maybe get used to how it looks on my hands ahead of time. You did a whole motorcycle in that stuff? Ouch!