25-PAH stove black glass

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rodbo1967

Member
Mar 5, 2012
45
New Jersey
Evening all,

I posted awhile back about my 25-pah turning black almost immediately after starting it up. A little back story, we have been using it for months with nearly no concerns. Now the black glass problem is back with a vengeance.

Everything has been thoroughly cleaned. Twice within 48 hours. My lower settings are 1/5/1. I am burning Nature's Own pellets and have not had an issues with them. Today, I cleaned it thoroughly. To the point of taking the exhaust apart and making 100% certain it was clean. The door gasket has been replaced.

Start up time 4:41, fire at 4:46 and blower on at 4:59. Glass turned black almost immediately. Flame does not appear to be correct.. Flames are high and what I would call lazy. I did a thorough cleaning a month ago and the stove ran great until a few days ago. When I open the door the black by product on the firebox ignites.

I am at a loss as to what else could be causing this issue. Any help would be terrific. I have an image to post, but the forum will not allow.
 
Are you sure the combustion blower fan is running at the proper RPM? It sounds like you have an airflow problem, and assuming you got all the passages cleaned out, I suspect the fan speed, or a damaged fan. You did remove the combustion fan to clean it, right?
 
Are you sure the combustion blower fan is running at the proper RPM? It sounds like you have an airflow problem, and assuming you got all the passages cleaned out, I suspect the fan speed, or a damaged fan. You did remove the combustion fan to clean it, right?

Yes, everything is thoroughly cleaned. Last night I adjusted the settings back to 1/4/1 and it was fine until this AM. Black glass again.
 
....not sure if the 25-pah is similar to my 25pdvc, but i get a buildup in the heat exchange passages that is only cleaned out properly with the LBT and compressed air. Caused frequent E1 shutdowns (poor airflow/vac loss) until I figured it out.
 
Yes, everything is thoroughly cleaned. Last night I adjusted the settings back to 1/4/1 and it was fine until this AM. Black glass again.
If it's burning dirty you probably want to increase the LBA not decrease it.

It's hard to guess at what the problem could be, if it's burning poor and it's not crappy pellets then it could be a whole host of things that all involve air, restriction in the OAK, in the venting, in the labyrinth of passage ways behind the firebox, combustion blower, one of the four gaskets on the stove leaking (door, ash pan, glass, hopper) either due to bad gasket or warped stove body, one of the seams/welds/silicone joints leaking air, warped cradle or burn pot allowing air to bypass the pellets, or maybe a controller problem with the blower speed, did I miss any other possible air flow problems?

I am sort of troubleshooting mine at the moment now too. I had it burning good enough to go about 2 weeks before deep cleanings last season but in the last month I can't seem to get it to run good even a day or two after a deep clean. I think I am getting heavy buildup in that labyrinth behind the firebox that is not getting cleaned out. I wish they didn't make it so hard to clean that out properly but maybe that is normal for pellet stoves i've never seen the internals of other brands.
 
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If it's burning dirty you probably want to increase the LBA not decrease it.

It's hard to guess at what the problem could be, if it's burning poor and it's not crappy pellets then it could be a whole host of things that all involve air, restriction in the OAK, in the venting, in the labyrinth of passage ways behind the firebox, combustion blower, one of the four gaskets on the stove leaking (door, ash pan, glass, hopper) either due to bad gasket or warped stove body, one of the seams/welds/silicone joints leaking air, warped cradle or burn pot allowing air to bypass the pellets, or maybe a controller problem with the blower speed, did I miss any other possible air flow problems?

I am sort of troubleshooting mine at the moment now too. I had it burning good enough to go about 2 weeks before deep cleanings last season but in the last month I can't seem to get it to run good even a day or two after a deep clean. I think I am getting heavy buildup in that labyrinth behind the firebox that is not getting cleaned out. I wish they didn't make it so hard to clean that out properly but maybe that is normal for pellet stoves i've never seen the internals of other brands.
Good info.... I too am having difficulty with a brand new 25-PDVC. I'm burning Blazers and the stove is filthy after about 8hrs. Makes no sense since my upstairs 25-PDV is burning the same pellet and RUNS GREAT! My glass is dirty starting on the bottom right then goes right to the top. Quite frustrating when one works great the and other NOT SO! Nonetheless, they both give off good heat so I guess that's what matters the most ...