dirty glass

[cyclone]

I have posted on this topic before and not received any responses. Here it goes again.

My stove is a Harman TL 300. This is my second year with the stove and I think I have a handle on the operation of this unit. However when I get the afterburn kicked in and longer burns my glass blackens.

My wood is seasoned, abut two years old. I am burning clean with no smoke coming from the chimney. Inside of the stove my firebrick is clean (white) after a full burn. My door gasget is new and snug. I will be installing a Outside Air Kit this weekend. This may help.

Why am I getting the blackened glass?

 

[Todd]

Could be a draft issue? What's your chimney set up?

 

[cyclone]

outside masonary chimney. Clay flue's.

Have had in the past over a long period of burning pressurization issues.

Wondering if the outside air kit I am going to install will help with this issue also.

Thanks for the reply

 

[Todd]

The OAK may help some but i'm betting it's the cold outside clay line chimney that's causing the problem. Are the clay tiles the same size as the stove exhaust collar? The stove is probably burning fine once the chimney comes up to temp but when you turn it down to a low burn the chimney probably cools down some and reduces draft and causes the dirty glass. An insulated liner would keep those flue gases warmer.

 

[branchburner]

I had that problem with my Oakwood last year. So far this season, no problems. A few things I am doing differently: more primary air early in my secondary, and loading/repositioning so the splits are more to the rear of the firebox. Obviously the latter is something I'm not going to do with a full load in the middle of the night. But instead of just leaving a half load to burn as it sits, I've been opening the top and pushing coals and splits to the back when possible. Since that is where the seconday burn takes place, that part of the load burns down faster. When I do have black glass, I've sometimes noticed more charcoal near the front door and just ashes to the rear. I'm guessing late in the burn there wasn't enough of a coal bed to the rear to keep the secondary burn going and the front log smoldered.

 

[bluefrier]

Some air wash are designed better than others. If it's only dirty on the long burns maybe you are turning it down too low. I wouldn't worry too much if the burns are smoke free though. Just burn a nice hot fire the next morning to clean things up.

 

[savageactor7]

Just riftfng on bluefrier's thoughts and yeah it could be a Harman TL 300 thing so wait until some Harman owners check in. If it's not too late maybe you could edit post topic to mention 'Hatman' stove dirty glass question.

Many stove' glass will blacken on long burns but a good designed air wash will self clean dirty glass in a good 30 minutes or so in a hot burn. Did you try burning hotter to see if it cleans up?

 

[EatenByLimestone]

Is your gasket clean? Sometimes ash will pack itself into mine and ruin the seal.

Matt

 

[Diabel]

You are cutting the air too fast or your wood is not fully seasoned.