Pellet Pile Ups, Low Heat, and Black Glass

I’ve had two phone calls and one email this morning about this same issue and I haven’t even made breakfast yet so I figure I should address it here.  This is the situation of having a very lazy flame that is smothered by incoming pellets usually accompanied by the glass getting black.

The most common cause of this is a build up of ash in a stove and chimney.  If you have not cleaned your stove, check out my earlier blogs.  I have one dedicated to cleaning stoves and even a youtube video showing you how to do it.

If you have already cleaned your stove and still have the problem, it’s time to consider that you have a leaking door gasket, or an leaking ash drawer gasket, or a bad exhaust motor.

Consider the physics of a pellet stove.  The basic design is like a car; you have an air intake manifold, fuel (in this case, Wood Pellets), and exhaust.  The exhaust fan literally sucks air through the burn pot causing combustion.  In an ideal setting, air is only being sucked through the air intake manifold.  In a less than ideal setting, air is being sucked through other places as well which compromises burn efficiency.  That’s when you get pellet pile ups, lazy flame, and black glass.

The most common areas of failure are the previously stated door & glass gaskets, and ash pan gasket.  If these are failing, they are allowing air in that is not routed through the burn pot, so the pellets are not burning very well.

One gentleman that called me today told me a horror story of how many parts his dealer had him replace and he still has the problem.  The laundry list started with a wiring harness (in more than a decade of stove repair I’ve only replaced one of these), then it went to the control board, then the snap switches.  It includes having to pay the service tech to come to his house and on several occasions bringing his stove back to the dealer along with hours spent on the phone with tech support.  By the end of the call be both agreed that his dealer is an idiot and a crook!  What a nightmare!

Here’s the sequence for repairing this problem;

  1. Clean your stove and chimney (see other blog and video).  Make sure damper is open all the way if you have one.
  2. Replace Door & Glass Gaskets and Ash Drawer Gasket.
  3. Replace Exhaust/Combustion fan.
  4. Replace Circuit Board.
  5. Send it to the smelter and have it melted down into shiny lumps.

In more than 10 years of repairing pellet stoves I have never performed actions 4 & 5 on the above list to fix this problem and neither should you.  So before you get that far contact me or another professional for advice.

Ok, time for me to make breakfast, take Jonas on a walk, ship my parts and get busy on my other projects.

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Posted in Augers, Exhaust/Combustion Fans, Troubleshooting

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