Quadrafire Mt Vernon AE loud humming and vibration on initial start up

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psjunky

New Member
Jan 28, 2018
3
La Grande
I’ve owned and operated my Mt Vernon AE stove for approximately 8 years. Besides the occasional igniter replacement and the fouling of the augar optical sensor I have had very few issues with this stove. I burn a premium brand of softwood pellet (red fir/pine) and clean the stove every 200 lbs of pellets (once a week during colder weather). This year the stove has developed a loud hum accompanied by brief vibration noise during the initial start up faze. It last for about 30-60 seconds while the combustion blower is pulling the hardest then quiets down and functions normally for the duration of the burn. I assumed it was a sign that the combustion motor bearings were showing their age and I replaced the motor and fan. To my disappointment the same noise is present with the new OEM motor and fan. I have inspected and cleaned every inch of the intake and exhaust system thinking that there might have been an obstruction blocking the free flow of air during high fire but have found nothing to substantiate that theory. I’m running my stove in automatic/softwood, flame height at -4 and deferential temp at 1.5 and convection blower on “quiet”. Anyone have any suggestions on where I should look next to solve my noise issue?
 
At times, if there is too much fuel I the pot, it will block the pot holes and make that "howling, vibration" from the air trying to get thru the holes. This is with a fire going of course. kap
 
I’ve owned and operated my Mt Vernon AE stove for approximately 8 years. Besides the occasional igniter replacement and the fouling of the augar optical sensor I have had very few issues with this stove. I burn a premium brand of softwood pellet (red fir/pine) and clean the stove every 200 lbs of pellets (once a week during colder weather). This year the stove has developed a loud hum accompanied by brief vibration noise during the initial start up faze. It last for about 30-60 seconds while the combustion blower is pulling the hardest then quiets down and functions normally for the duration of the burn. I assumed it was a sign that the combustion motor bearings were showing their age and I replaced the motor and fan. To my disappointment the same noise is present with the new OEM motor and fan.
I have inspected and cleaned every inch of the intake and exhaust system thinking that there might have been an obstruction blocking the free flow of air during high fire but have found nothing to substantiate that theory. I’m running my stove in automatic/softwood, flame height at -4 and deferential temp at 1.5 and convection blower on “quiet”. Anyone have any suggestions on where I should look next to solve my noise issue?
Thank you for the reply. It’s a great suggestion and may be an explanation for why the magnitude and duration of the howling and the vibration varies. Is there a setting on the stove that determines how many pellets are dumped into the fire pot during the ignition cycle or is it possible that the igniter is getting weak, delaying the ignition time so the auger continues to feed pellets until ignition is confirmed?
 
the initial dump of fuel is pre-determined on what fuel is being burned. Then firepot thermocouple has to sense heat from a fire, to start feeding cycle. So there is no over feeding due to a slow start, but a slow start can cause a small fire to have to catch up, which can act like an over feed issue. The flame height adjustment is the fuel feed rate. You can use a mirror and flashlight to look at igniter slit, to see if there is any blockage from clinker debris. Double check that all holes in firepot are clear. Only other thing is different batches of pellets can be made different, so they burn different. kap
 
Thank you again kap for the prompt reply. I’ve investigated the possibility of blocked inlet ports in the fire pot and found no blockage or the presents of any klinkers so I change my fuel setting from “softwood” to “utility” and the howling and vibration have gone away. Am I to conclude that the “softwood” setting was over feeding the fire pot on initial start up and possibly blocking some of the inlet ports? Also, does the combustion fan ramp up to a greater speed when on the “softwood” versus “utility” setting on initial start up?
 
I believe it does so as to blow some of the ash out of pot as softwoods are high ash fuel compared to hardwood. As I stated too, it could just be a bad batch of fuel also. You could also tried going to -5 on flame height adjustment to see if it helped on softwood setting. I have an 06 model and I have to run on -5 to have any kind of chance to keep flame under control. Quad is still stumped by it. lol Stay warm. kap