When the auger does not feed pellets forward
There are pellets in the hopper, but the burn pot remains empty, or the stove ignites and shuts down again shortly afterwards because the pellet feed stops. If the gear motor hums without the auger turning, the auger is typically stuck in dust or jammed pellets, or the gear is worn. If the motor is completely silent when the stove needs to dispense, it may have burned out.
Before fitting a new gear motor, the auger must be free. Empty the hopper, remove dust and jammed pellets, and check that the auger can be turned easily. A new motor on a blocked auger will have a reduced service life.
The gear motor is only one of three motors in the pellet stove. If the stove gives an alarm for smoke or draught, or the pellets burn poorly, it is more often the flue gas extractor, and if the heat does not reach the room, it is the fan.
Five things that must match
The speed determines how many pellets the auger feeds forward in each interval, and it varies from 1 to 5.6 per minute. Even within the same brand, there are gear motors with both 1.0 and 1.5 revolutions, and an incorrect motor dispenses too many or too few pellets.
The shaft must fit the auger. Most have a solid shaft of 8.5 or 9.5 mm, while others have a hole into which the auger shaft is inserted. The voltage is normally 230 V, but some round motors run on 24 V, and the two cannot be interchanged.
The direction of rotation is typically stated on the motor label as CW or CCW. A motor that turns in the wrong direction pushes the pellets back into the hopper instead of forward. Find the right one among gear motors clockwise or gear motors counterclockwise.
Finally, it must be determined whether the stove uses an encoder. A gear motor with encoder reports the revolutions back to the control system, and if a motor without an encoder is fitted in a stove that expects the signal, the stove goes into alarm.
Before fitting the new gear motor
Some stoves, including those from Extraflame and Thermorossi, have an extra gear motor that drives the automatic cleaning of the burn pot. It resembles the auger gear motor, so check that the motor you order is for the auger.
The gear motor is suspended in rubber mounts that dampen vibrations and resonance from the motor. The rubber can harden over time, and new mounts when replacing the motor provide smoother and quieter operation.
