2010 Harmon Accentra Freestanding Feeding Noises

[afranch]

I've searched for information about this but all the posts I've found relates to chain driven stoves and I understand that mine isn't chain-driven being a 2010 model.

The stove is feeding pellets fine, but rather than whirring with the rare clunk where a pellet gets chopped it makes more frequent clunks/pops and the operation sounds more strained. Some of the clunks are somewhat elongated sounds with a slightly grindy/strained character to them.

I have recently cleaned the fines out of the feed chamber and have been keeping the stove clean. I have not cleaned the auger tube since putting the stove in the operation...not sure how or if this is the first step. This season I did start burning Country Boy White Lightning Pellets which I've noticed make cleaning the burnpot of carbon deposits more frequent & difficult, so maybe there's a build up somewhere?

Any help appreciated!

 

[Lousyweather]

hmmmm....so, the fines chamber IN THE REAR of the unit (not the igniter chanber) has been cleaned? check

Does your unit have a 5 hole burnpot? (5 holes at the base of the burnpot)

Does your unit have a bypass tube?

Does your slide plate have any water-soluble yellow/brown/black deposits on it?

 

[P38X2]

Make sure the auger area in the burnpot is clean. Carbon can get built up in there and appear to look like part of the burnpot. Not explaining myself well but grab a good flashlight and look closely in that area.

Mine was making a similar, and possibly identical, noise a while back. Empty the hopper completely, vacuum any fines in there, hold down the hopper switch and put the unit in test mode. Watch for jerky movements of the slide plate. As it's moving, tap the top it with the back of a screwdriver. Sometimes fines get caught towards the end of the area where the slider seats itself when in the closed position. It'll cause the auger linkage to cam over causing a popping sound.

Don't assume cleaning the fines box alone will remedy the situation. It only stays it test mode for so long using this method so you may have to turn it off then back to test to have enough time. EDIT- Also, you'll need to stick a towel or something in there to fake the vacuum sensor. Make sure the towel doesn't get caught!

Before doing all of this, try and stick your head back there and see if you can see the actuator bearings camming over. It'll be obvious if this is the problem.

 

[Tiggar61]

Make sure the auger area in the burnpot is clean. Carbon can get built up in there and appear to look like part of the burnpot. Not explaining myself well but grab a good flashlight and look closely in that area.

Mine was making a similar, and possibly identical, noise a while back. Empty the hopper completely, vacuum any fines in there, hold down the hopper switch and put the unit in test mode. Watch for jerky movements of the slide plate. As it's moving, tap the top it with the back of a screwdriver. Sometimes fines get caught towards the end of the area where the slider seats itself when in the closed position. It'll cause the auger linkage to cam over causing a popping sound.

Don't assume cleaning the fines box alone will remedy the situation. It only stays it test mode for so long using this method so you may have to turn it off then back to test to have enough time.

Before doing all of this, try and stick your head back there and see if you can see the actuator bearings camming over. It'll be obvious if this is the problem.

 

[Tiggar61]

Have harman p68 making same noises, Checked slide plate seems ok.

 

[P38X2]

Could just be the pellets if everything checks out. I test burned a bag of softies the other day and they were way crunchier than my usual brand. Nothing sounded out of the ordinary, just crunchier.

 

[Lousyweather]

answer to 4th line in my above post?

 

[Tiggar61]

No deposits on slide plate. Ran a couple of cups of pellets mixed with powdered graphite to lube things up. Still the get the same metal popping/snapping noises,not every vend though.

 

[ivanhoe]

sounds like we are having the same symptoms with our auger noise only mine been chain driven. it could very well be the pellets getting crunched by the slide gate, food for thought!

 

[afranch]

Thanks for the suggestions and here is an update:

More than 5 holes at base of burnpot, no deposits on sliding door.

Double checked fine box in back of stove I had previously vacuumed out. Not many fines but this time there several pellets in the area. They were not under the plate metal piece that moves but off to either side. I don't recall getting many pellets back there previously & don't know if that's normal....the pellets I'm burning this year are much shorter than previous years. I cleaned these pellets out and in test mode there is no more popping. I'll see if that was the issue. Might just be with these pellets I have to clean out the fine box much more often than usual.

All the things P38x2 said sound very plausible. I am burning Country Boy White Lightening Pellets this year and I've noticed they create an abnormally large carbon build up on the burn box that's tough to get off (got some good tips from this site though so now it's much easier). Didn't see a whole lot in the auger tube/augur area though.

I also noticed the popping/grating happened only when the sliding door was shut. Did you mean stop up the hopper opening with a towel while my hand is in the hopper (to tap sliding door with screwdriver) so vacuum sensor gets faked out?

 

[mepellet]

I also get a lot of small pellets in my fines box. I have started to make cleaning the fines box a part of my weekly cleaning to monitor the accumulation. I get a small handful (maybe less than half a cup) of fines and pellets each week from the fines box. How does the fines box work? How do pellets make their way into it?

 

[Lousyweather]

I dont think the vac sensor is gonna cause any popping or grinding. A short pellet would tend to make the slide plate "pop" less. Does the bearing on the feed arm move freely and quietly? Have you taken the feed motor off and run it independantly (not connected to auger and slide plate). I wonder ifthat grinding isnt coming from the feed motor- a gear with bunged up teeth, or missing a tooth or two.....

 

[Tiggar61]

Afranch any luck on tracking down the source of your noise? I'm leaning towards the augar motor in mine maybe a stripped tooth on a gear? Everything else looks fine.

 

[rickwai]

To check for a jammed slide plate remove rear shields and move arm on back of feeder.It should move up and down easily. If it feels tight, the auger motor probably has a bad gear and needs replaced.