Ash getting into burn chamber - Harmon TL300

[DaveA-inCO]

I've had a Harmon TL300 now for around 13 years, and am replacing the burn chamber, shoe brick, and other cracked bricks for the 2nd time now. This time the repair is coming to around $1400... I could buy a new stove for that - but I like this top loader... I'm looking to you all to see if this is "normal" wear and tear, or if I have a problem.

The main issue I see is that the burn chamber gets filled with ash, holes plugged, etc. It then starts to break down. The shoe brick also falls apart in a 3-4 years of use. I burn 24x7 during the winter as it is my main source of heat. I burn mostly cotton wood - that's what I can get for free... The flue is a straight 6" pipe - no elbows, about 20' up to the top of a vaulted ceiling.

My theory is that the draft is so strong such that when I shut the bypass damper the sudden gulp of air causes ash to get sucked into the burn chamber. Would adding a flue damper help? I would think closing the flue damper just prior to closing the bypass damper then opening it back up to avoid that "gulp" of air.

Here is what the burn chamber looks like after 5 years of use:

 

[bholler]

I've had a Harmon TL300 now for around 13 years, and am replacing the burn chamber, shoe brick, and other cracked bricks for the 2nd time now. This time the repair is coming to around $1400... I could buy a new stove for that - but I like this top loader... I'm looking to you all to see if this is "normal" wear and tear, or if I have a problem.

The main issue I see is that the burn chamber gets filled with ash, holes plugged, etc. It then starts to break down. The shoe brick also falls apart in a 3-4 years of use. I burn 24x7 during the winter as it is my main source of heat. I burn mostly cotton wood - that's what I can get for free... The flue is a straight 6" pipe - no elbows, about 20' up to the top of a vaulted ceiling.

My theory is that the draft is so strong such that when I shut the bypass damper the sudden gulp of air causes ash to get sucked into the burn chamber. Would adding a flue damper help? I would think closing the flue damper just prior to closing the bypass damper then opening it back up to avoid that "gulp" of air.

Here is what the burn chamber looks like after 5 years of use:

View attachment 282389

That is very typical of what we see with these stoves. They are very expensive to maintain.