Lennox Whitfield Traditions Stove Air Flow Diagram -T300P

I've had my older (bought used) Traditions stove for 4 winters and I'm having a problem with partially burned pellets accumulating in the pot, choking out air flow, and eventually causing an error and the stove shuts down; I'm hesitant to leave it on when I'm gone.

The stove lights harder than I remember and the window is sooting up much faster.

I do not believe my draft is working as it should and I was hoping someone could provide a diagram of the airflow for this stove; neither the owners manual or service manual have any information. When I close my draft I get a lazy flame and as soon as I open my draft 1 notch the flame is active but once I move it past the 3rd notch, about 1/3 open, I get no change in flame intensity. With my 2 yr old Breckwell stove I can blow pellets out of the burn pot if I open the draft up all the way.

I called Lennox tech reps and they said there should be a change in draft for all positions but did not provide me any other info other than call a rep in the area for troubleshooting. I live rural so as soon as someone gets in their rig the charges start. But I've also read that these stoves have a poor air flow design.

What I have done:

Inspected and cleaned the 12' of 3 1/2 pipe which has 1 90 deg elbow.

Replaced the door gasket and checked seal.

Replaced the window gasket and ensured window wash gap at the top is correct.

Attached my shop vac to the Exhaust motor and I was able to feel air movement in the left and right voids in the upper portion of the fire box; I'm assuming that is where the exhaust flows and provides the draw for the draft. I don't feel the same air movement just using the exhaust motor but of course the door is open. I do feel air movement through the exhaust motor when when I start up the stove, before combustion as a test. I do not own an air movement meter.

Visually inspected the motors to see that they are both running when the stove it running.

I have to perform routine maintenance more frequently than previous years to keep the pot burning clean. Sometimes it will accumulate a mass of partially burned pellets in the pot right after I've cleaned everything so the problem is intermittent.

I took my stove off the wall thermostat so I can control shutdown and start up and we're pretty much running it 24-7 now unless we're gone for the day.

I thought it might be the pellets, Coastal Farms Premium, but it doesn't seem to matter which brand of pellets I'm burning.

I've read the permanant sticky at the beginning of this forum and read the few posts about this stove on this site.

Any other thoughts are appreciated.

Sure sounds like classic "dirty stove syndrome". Last time the stove was taken apart & cleaned (all ash traps opened & cleaned, burn pot scraped, comb. blower removed and cleaned w/ new gasket, etc, etc)?

Have you ever tried the leaf blower trick after a cleaning?

I'm just shooting in the dark here:

Did you look for ash traps on each side of the stove behind any fake brick panels?

Some whits even had traps inside of traps (so to speak).

Once you remove their covers you can do the brush and vacuum routine (also thumping the firebox walls will loosen up ash and make it fall down where you can get to it with a vacuum).

This same routine can be applied to any inner traps that may be there.

Then you can (make sure you have all of the replacement gaskets before doing this part) remove the combustion blower and use a brush and vacuum to go from there into the back passage of the exhaust system.

I haven't seen any air flow diagrams for that particular stove but I'm sure some others on here have either seen the stove partially disassembled or a service manual for it.

My plan is to take the stove outside next summer and give it a good vac and blow... Probably solve my problems.

I do the routine cleaning on every bag of pellets since this problem started, sometimes more often when the pot clogs up. Within the last week i removed the brick lining, cleaned all ash, scraped the burn pot, dumped ash pan, scraped tubes, put my shop vac on my exhaust motor to suck as much as I could, and just last night when we got home with the feed on low and high fan the burn pot was clogged with partially burned pellets.

I may try to remove the exhaust motor but getting to the nuts is a pain and was hoping to put this off until summer.

Thank you for the reply.

According to the users manual and service manual I have the only trap is the sliding door that drops the ash into the removable drawer.

I took a screw driver and tapped all along the fire box and it is solid throughout except for the 2 voids at the top next to the heat exchange tubes for air flow and the slides where the ash drops into the drawer.

It sounds like I need to remove the combustion blower. Just to confirm, the combustion blower is what creates the negative pressure within the fire box and moves the air out through the exhaust.

Thank you for your reply.

Yup you nailed the combustion blower.