This is a common situation we see with St. Croix stoves, especially older models. In most cases it appears the stove is overfeeding or feeding fuel continuously, when in fact the issue is with proper air-flow.
Dennis Writes In:
I have an older Prescott series St Croix stove that is not working properly. It continually feeds pellets and overfills the burn pot. The auger never quits. Any suggestions?
Mr. Pellethead Replies:
Dennis, We are happy to assist. When you say that the unit feeds continuously, does the auger motor not stop turning? Inspect the feed motor while in operation (After the start-up cycle). If it is truly turning constantly and does not stop then that would indicate a control board issue. If the motor is starting and stopping and you see differences in the start and stop timing as you go to different heat settings than it more than likely is not the control board. In most cases where you are having this issue will be one, or a combination of the following.
- Ash blockage. Inspect & clean the vent pipe, combustion housing, firebox ash traps and heat exchange area.
- The ash drop/shaker is not closing completely underneath the burn pot area. That shaker rod needs to be pushed all the way in during operation. Over time ash build-up down there can prevent it from closing fully. Remove your burn pot and versa grate plate under the burn pot to thoroughly inspect and clean this area.
- Burn Pot & Versa Grate Shaker Plate. Inspect both the burn pot and shaker plate beneath. Make sure there’s no areas burned through and that everything is seating correctly; firepot has no air-gaps, seating securely against the firebox floor.
- Shaker plate to burn pot bottom clearance – should be no greater than 1/16 inch (out of adjustment or worn versa grate shaft bushings). Too great of clearance reduces air velocity through the pot air holes.
- Gasket leakage. Check both your door and ash pan gaskets. Use a dollar bill, put half in and half out, close the door and see how much resistance there is. Check every few inches around the firebox door and the ash pan door. Should be significant resistance. –Typically gaskets go 6-8 years on average before needing to be replaced.
- Air Intake. Check for ash accumulation in the intake tube below the burn pot – commonly overlooked and not always visible. Make sure the rear damper is set correctly. For 99% of installations, stick a pencil in the intake, close the butterfly damper down on the pencil and pull it out. This is as much as the damper should be open.
- Your Combustion/Exhaust fan. The motor itself could be weak/no longer providing correct voltage or it could just be ash blockage in the housing there. You can use a volt meter to test the combustion fan. After start-up cycle it should change voltages between each heat setting.