Coal stove running hot.

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jonpard

New Member
Feb 26, 2022
1
Allentown PA
I have a Franco Belge shaker stove, and the last couple of days it's been running hot. I turn the temp. control down, but it still runs hot. I'm not sure why this is happening, it must be getting air from somewhere. Could anything happen from the heat exchanger back to cause this? Or is it air getting through before the fire box? Any ideas would be greatly appreciated.
 
Most likely the stove has developed an air leak or leaks. Check the usual suspects like ashpan door seal, main door seal, etc. Also, empty out the stove as soon as possible and do a thorough check for cracks and seam leaks.
 
With the smoke from an incense stick, or shake out a match, go around all doors (and fill lid on top) to see if the smoke goes into stove, or if it drifts away like it should. This will show you air leaking in. Check for leaks below grate first.

If you find none, you may have to remove any panel covers to get down to firebox to check for leaks between cast iron parts the same way. You will see the smoke be pulled right in.

If this is a model with glass door, does the blue flame above coal look much bigger than before?
The area of a leak should have a large flame.

If you have a barometric damper, make sure the flapper is not staying closed.
I have a Hitzer hopper fed coal stove running this winter and the last load of coal I picked up a couple weeks ago has been hotter than normal. Even closed the air down more, and the glow has been very even and brighter than usual. Not going through any more coal than usual. Found no leaks, I believe my enhanced performance is due to fuel.

Is your coal size the same as always? Larger pieces have more airspace between them and burn faster. You get the same BTU from any size of the same coal, just a different burn rate.

A leak into heat exchanger doesn’t feed the fire air. A coal fire burning harder than normal is an air leak under air he grate allowing more air up through the coal bed. Excessive secondary air above the fire won’t cause it to burn hotter. That allows indoor air to leak in above fire and slip up the chimney, cooling it, slowing the fire. Heat exchanger leaks above the fire do the same, slowing fire since air is reduced going through coal bed.

If a hopper door leaks, or another leak into hopper anywhere, when coal is low in hopper (1/4 to 1/2) turn off lights and look in when dark. It will be glowing in hopper. The hopper door lid will be unusually hot as well.
 
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