Harman TL300 smoking

[brokenknee]

Installed the Harman last January, I have had problems with smoke in the house since the install. I have disassembled the pipe in the house and put a liberal amount of motor cement in the connections to try to stop this issue. I due not believe it is a wood issue as I am burning ash the was c/s/s two years ago. I do not have a meter, but i can almost light the stuff with a farmers match.

I have called the dealer and he said he is at least two weeks out on service calls, which is understandable this time of year. He told me he thought I may be chocking down the damper to much causing it to smoke. I told him that while I do run it on the second notch the stove top thermometer is always in the white zone. I told him when I open the damper more than the third notch the stove will go into the red zone.

I also asked him if he thought I should extend the chimney as it is on the bottom end of what Harman says is the minimum height, about 15 feet. He said he tried that on another customer and it did not help.

Any thoughts would be welcome. While I like the smell of smoke at the campfire I do not like it in my house.

 

[Gboutdoors]

I have been burning with the TL300 for three seasons now and the only time I have got smoke in the house was do to poor draft. You said your stove top temps get to hot? I have never checked my stove top but have a burn indicator on my single wall stove pipe 6-8" above the stove.

Even if you are running it chocked down there will be NO smoke if it is drafting properly. There could be a leaking gasket but then it would burn hot even with the damper at the second notch.

Is this all the time or only with the afterburner damper closed? Are you getting the burner to light off properly? I had issues with this as it takes some time to learn this stove and how to run it.

How new is your house ? Is it REAL tight as this can cause negative pressure in the house and you will need out side air to get a good draft going. This happens to me on winter days with really low outside air pressure. I just need to crack the window near the stove a bit to get the draft going then close it. They sell a kit for outside air for the stove.

Sorry for the long answer but it can be one or more of many things. The TL300 can be a hard stove to get used to but once you get it down you will love it.

Only trouble I find is that it heats to well. We have a 2400 sf new home and we have to control the heat output.

So with all I threw at you the short answer is almost always DRAFT did I say it could be a draft issue.

Good luck and keep in touch and let me know how you make out.

Greg B.

 

[brokenknee]

I have been burning with the TL300 for three seasons now and the only time I have got smoke in the house was do to poor draft. You said your stove top temps get to hot? I have never checked my stove top but have a burn indicator on my single wall stove pipe 6-8" above the stove.

Even if you are running it chocked down there will be NO smoke if it is drafting properly. There could be a leaking gasket but then it would burn hot even with the damper at the second notch.

Is this all the time or only with the afterburner damper closed? Are you getting the burner to light off properly? I had issues with this as it takes some time to learn this stove and how to run it.

How new is your house ? Is it REAL tight as this can cause negative pressure in the house and you will need out side air to get a good draft going. This happens to me on winter days with really low outside air pressure. I just need to crack the window near the stove a bit to get the draft going then close it. They sell a kit for outside air for the stove.

Sorry for the long answer but it can be one or more of many things. The TL300 can be a hard stove to get used to but once you get it down you will love it.

Only trouble I find is that it heats to well. We have a 2400 sf new home and we have to control the heat output.

So with all I threw at you the short answer is almost always DRAFT did I say it could be a draft issue.

Good luck and keep in touch and let me know how you make out.

Greg B.

I watch stove temps temps really closely, If I do not choke it down the temps will rise into the red zone. I have double wall pipe up to the ceiling were it transitions to the class A pipe.

The smoking normally occurs once the afterburner is engaged. It may be fine for awhile and then start to smoke. Not sure how to tell if the afterburner is lighting off all the time or not; some times I hear a roar once I engage it and other times I do not. Once engaged the flame all but disappears. I am satisfied with the burn times of 8 to 14 hours depending on how I pack the stove.

My house was built in 1965, and I put an addition and all new windows last year. I would say it is fairly tight now but not as tight as a new house would be. I have a fan blowing behind the stove and other fans blowing the cool air towards the stove. The house is a 1,600 sf slab home and yes even in our region this is more than enough stove to heat the place. Minus 20 is common and last year we had five or six days were the low was a minus 30 F or below, almost hit 40 below one night

I asked the dealer about the draft as I thought I would add a two foot section on to the chimney. He said he did not think that would help as another customer had the same problem I do and tried it. He is saying I cut the draft down to much. Now this is my first EPA stove, but my old northern leader I could cut the draft completely off and it would not smoke in the house.

 

[gzecc]

Add two feet and see if it helps. Every house dynamics are not the same.

 

[Gboutdoors]

gzecc could be right you will need to try many ideas to find the cure. I can shut the draft down all the way with no trouble at all and with or with out the afterburn shut you should also. I am 99 percent sure it is some kind of draft issue.

Ps I have found that many stove dealers do not fully understand the many things that can affect draft . I learn something new every season.

 

[brokenknee]

I took off Monday as Tuesday I have off for Veterans day. I think I will make a trip to the dealer if the weather permits; about a 70 mile trip one way. We just got back from Superior WI and have about and inch and a half of snow on the ground and it is still snowing. I do not think he is open on Sunday. Hopefully the snow we have will melt as I have a metal roof and I am not about to climb on it with the snow.

The dealer did finally agree to come take a look but as I stated earlier he said he is at least two weeks out. He does not make appointments but calls you a day or two before he can make it.

 

[brokenknee]

It appears the gasket on top door is leaking. Here are a couple of pictures. Notice the gasket appears discolored toward the top of the picture. . Also notice the soot on the left side of the picture (second picture), I sweep the top with a small brush after each reload to clean any debris that may have gotten on it when adding the wood. This stove was just installed last January, not sure how long it sat in the showroom floor.

 

[Gboutdoors]

That is for sure at least part of your problem if that soot comes during a burn. Now that you mention it I have had smoke a few times after top loading and a small wood chip would hold the gasket up. I take the gasket and pull it down every few loads. This will also help to keep it tight as it tends to flatten out over time. Have you cleaned the back of the stove? This can only be done threw the top stove pipe opening. I find that can also affect your afterburner draft. I would ask the dealer to show you how when he comes as this is a very delicate area of your stove. Also have you checked the gasket on the afterburner damper. If you look at the owners manual it shows you how to check and adjust this damper. Mine needed to be adjusted after a few months of use and has been good since.

 

[Gboutdoors]

So Brokenknee how did you make out with your visit to the dealer? Did you fix the top door gasket.

 

[kennyp2339]

It may be a dumb question, but when was the last time the chimney swept? I would double check the chimney (upper portion) and the cap to make sure there aren't any blockages ie:soot, bird, nest ect. Also how tall is your chimney system? And what is the geographical location of your house, you could be experiencing a micro inversion with negative pressure.

 

[1kzwoman]

There is an adjustment of lid cam outlined in my Exception by Harman owners manual. There may be one in your's too. Also check that your ash/bird screen is not blocked with creosote as others have suggested.
Also it's a tadpole style gasket...there is a tail under the edge of the metal liner on the lid. You can gently squeeze the bulb part of the gasket to fluff it up the tail will hold it in place. That liner has acorn nuts holding it in place you might gently tighten them.
Also try pulling your coals forward away from back of stove/afterburner intake. There are several people who know more about downdraft stoves who will chime in I'm sure.

 

[1kzwoman]

Also these stove require DRY wood, and don't shoulder well. Burn 24/7 at -30 with dry wood and you will love a downdraft stove

 

[brokenknee]

Sorry for the late response, was out of town for work last week, then I'm in the middle of remodel of my entry way.

Chimney was swept right before I started burning this fall, very little creosote build up.

Wood is ash c/s/s two years ago. No moisture meter but it will almost light with a match. It's dry.

Never made it to the dealer last week as I did not feel like making the long trip driving in snow.However dealer (owner) came out last Sunday to look at it. He did a complete tear down on the stove. The only thing he found is what we have already discussed; a "weak" gasket on the top of the stove. He told me there are no adjustments on the lid of this stove. The dealer also mentioned that burning 24/7 I should do a complete tear down / cleaning once a year. It took him about an hour and a half to do.

I asked what is the typical life span of the after burner, he told me 24/7 burners usually get two to three years out of them before needing replacement and they cost around $350. I thought i read on here they last about five years, but that may have been in a different climate were they do not have to burn them as hard. He said mine looked good at this time, but then I only burnt the stove for less than a season total.

As far as the smoking goes, as long as I "fluff" the gasket every reload, for the most part I do not have any smoke in the house. Once in a while there may be just a hint of smoke, I guess I can live with that for now. Will have to see how it goes once it starts warming up again in about 6 months.

 

[1kzwoman]

The bottom r corner of gasket looks funky kinda twisted. Loosen the acorn nuts and ease that to a better fit. Or take old one off and go to local hard ware store and get more gasket. Any spot that feels crunchy is leaking.

 

[Gboutdoors]

Just another thought is the top door flat or does it have a curve or bend in it as this could make it sit wrong also.

 

[razerface]

i dont think the gasket is causing the smoke. I can open my top any time during the fire cycle and leave it open,,never get any smoke out of it.


If you have a lack of draft the smoke may come out the stove into the room instead of going out the stack. Back puffing will lift the lid and release smoke and ash out the top.

If gasket is leaking with proper draft, it would suck air INTO the stove and get hot,,,not the other way around.

 

[1kzwoman]

Razr I agree but how does he get a clean gasket print under the lid on stove top with creosote flakes on the side of gasket away from firebox. If I look at photos that's what I see?
Unless the backdraft is leaking enough smoke to build up soot on cut outs on stove top.

 

[razerface]

I would sit down and watch a complete burn cycle. By the end of that you will know when it happens, and possibly why

 

[Gboutdoors]

I agree as I said from the start most likely a DRAFT issue. But if the top door gasket on my TL300 is held up by a chip of wood during reload and then the down draft damper is shut I have had smoke come into the room. I can not open the top load door if the down draft is on I don't know about yours razerface.

He said in an earlier post that it happened after the down draft damper was closed. This shuts the draft in the front and top of the stove off and sends smoke to the back lower end of the unit. This would allow smoke to come out a leaking gasket on the top load door I think.

 

[razerface]

It should not smoke even if top load door is leaking. I just opened mine 1 inch while dampner was closed, left it open until digital said i was getting hot,,,,no smoke. I could hear and see the fire roar from the new air supply. Draft kept the smoke going thru the chamber and out the stack,,just like always. I am about 1-2 hours into my burn cycle, so i will try again right after next reload.

You can open your top to try it. Grab it and lift,,not with the handle, but grab the top ( wear gloves!) or do what i did,, i threw a bolt down under the lid and closed the handle. The bolt held the top up and did not let the gasket seal even though the dampner closed and rerouted the exhaust. No smoke out the lid. I have excelent draft.

I have had smoke on a back puff when opening top door before. It only happens if i have air shut down too far when i open top door and it is above 30-35 degrees.

 

[begreen]

I also asked him if he thought I should extend the chimney as it is on the bottom end of what Harman says is the minimum height, about 15 feet. He said he tried that on another customer and it did not help.

Any thoughts would be welcome. While I like the smell of smoke at the campfire I do not like it in my house.

So he has run into this problem before. Not surprising. These stoves are fussy about draft. I would add more chimney. 3-4ft if possible.

 

[razerface]

Razr I agree but how does he get a clean gasket print under the lid on stove top with creosote flakes on the side of gasket away from firebox. If I look at photos that's what I see?
Unless the backdraft is leaking enough smoke to build up soot on cut outs on stove top.

dont know, but why would the gasket outline remain clean? The creosote jumped over it to land on the other side?

 

[brokenknee]

I agree I will have to add more chimney, I have about two to three feet above the roof now how much can I add before additional support will be needed? I would prefer not to add more than I need as I am concerned about the aesthetics.
.

 

[brokenknee]

I have not added the chimney yet as there is snow on the roof. Not sure if this will have to wait until spring or not, they (weatherman) are talking of a warm up and hopefully the snow will slide off my roof.

The smoking seams to have gotten worse since the visit from the dealer. The wife want to stop using the stove altogether.

I was wondering if an OAK would help. The house is not new, so it is not "air tight" I really need to get this figured out as electric baseboard is really costly. I do have the P68 pellet stove but really don't care for that either, and went through four ton of pellets in just a half of season using it last year.

How does one go about measuring draft with a manometer? I would be open to purchasing one to help solve the problem.

 

[branchburner]

The smoking normally occurs once the afterburner is engaged. It may be fine for awhile and then start to smoke. Not sure how to tell if the afterburner is lighting off all the time or not; some times I hear a roar once I engage it and other times I do not.

I have a fan blowing behind the stove and other fans blowing the cool air towards the stove.

Now this is my first EPA stove, but my old northern leader I could cut the draft completely off and it would not smoke in the house.

I do not think an OAK is needed. Could be a draft problem, or your operating technique, or both. If you get a thaw, try to add that chimney.

This stove is very different from your old stove, and from other EPA stoves, for that matter. Downdrafts are the trickiest stoves of all, because to get good secondary combustion they require both good draft AND a proper sequence of establishing a deep coal bed and hot fire, then close the bypass, and then reducing the primary air in increments. You generally CANNOT shut the air down too quickly without stalling the AB, and potentially getting backpuffing. I agree with your dealer, this may be your problem.

It is true the stove will get very hot, before shutting the air and bypass, when trying to get a good coal bed. What are the actual temps you are talking about? My stove is a bit different, but it is not unusual to go well over 700f (and the flue even higher!) when the bypass is open. As soon as I shut the bypass, however, temps drop so I do not have to worry about shutting down the air supply right away.

If I am burning with the bypass open for a longer time, then I DO need to close the air to prevent overfiring. So sometime I have the air fully shut with the bypass open, as I'm getting sufficient coals in the firebox. Then, for just a few minutes before closing the bypass damper, I will open up the air control to 75% or even 100%. The temps rise rapidly, but then stop rising as soon as I do shut the damper.

At that point, I might leave the air at 75% for 5 minutes, 50% for another 5, then 25%, then let it cruise at 10-15% open. ALWAYS a gradual decrease in air. How do I know the secondary is still firing in the AB? With my stove, I can measure the exterior stove temps on that rear burn chamber. If the AB is engaged, they will quickly rise to over 500f, sometimes up to 800f. If I see them fall below 400f, I know the AB stalled.

Do you see smoke coming from the chimney outside when the bypass is closed? If so, that is a sign the AB has stalled. Sometimes it will stall when a log in the firebox has rolled up against the shoe brick, blocking the flow of gasses into the AB. Sometimes it will stall when the splits are too big for the amount of coals, and then I need to put some small splits or branch wood in the back of the firebox to coal up faster and burn hotter. Sometimes it will stall when the fan blowing to the back of the stove is on high, and cooling a stove that was only borderline hot enough.

So as well as adding some chimney, try switching around other variables: when you close the air, the bypass, depth of coals, size of splits, etc. It's not going to be like the old stoves you can set and forget. The downdraft stoves require babysitting and learning a technique that works (hopefully) for each specific flue setup.