Intermittent Auger Power (Avalon 900)

Johnny_I

New Member
Jan 20, 2018
5
CT
Hi all,

I have had an Avalon 900 ('93-'96) for ~9 years, have replaced most parts throughout the years, give the exhaust pipes and cleanouts a thorough cleaning every month or two, but am now running into a new issue I just can't figure out. Any insight you can provide in order to avoid running the electric baseboard heat is greatly appreciated!

Upon starting up the stove it may run just fine for anywhere from at least ~30 minutes, to a few hours, to even a couple of days before the auger motor will suddenly stop turning. Sometimes it's able to recover and resume turning before the flame goes out, and then keep going for a while before stopping again, sometimes not and the fire dies. Both the exhaust and blower fans run without issue.

I installed a brand new hi torque auger motor last week, but the issue persists. Also tried a brand new cycle timer yesterday, sprayed electrical contact cleaner into the burn rate dial, stripped and replaced the electrical connectors with new leads, yet same thing. I also have the negative pressure switch wires tethered together to rule out that factor.

Oddly, just now when it stopped turning (for ~30sec), I pulled the leads off the 220F snap disc, then reinstalled them and it cycled for an interval or two before stopping again. I then tested tethering the 220F snap disc wires together with a jumper to rule out a faulty disc, but the issue still persists; it'll go for a few cycles then pause for a while (~30-60sec before starting again, if at all).

There is no jam in the auger, I can turn it freely from the back without the motor on without much resistance (at most slightly gummy but nothing the auger shouuldnt be able to handle), and only have about 64oz of pellets in the hopper during these tests.

When the motor does stop turning, I do still hear the cycle timer "click" on at the intended interval, but don't hear any attempt in the motor to turn (not even an interrupted grunt, as if it were trying to force through a stuck bearing). It's as if its just not getting power for a few cycles despite the cycle timer still clicking at the proper rate. Sometimes the motor may give a faint half-second twirl instead of the normal 2.5 second rotation, and when it does somwtimes I hear a very faint squelch.

Again, it runs perfectly well, turning very strong upon startup, and with a vigorous flame for at least a full 30 minutes (sometimes more). Sometimes it may run for hours, overnight, or a couple of days before starting to intermittently stop.

Pulling my hair out. Naturally it died the night before each of our recent snowstorms.

Truly appreciate any insight you can provide.
 

Ssyko

Minister of Fire
Nov 6, 2017
3,006
Lorraine NY
Hi Johnny welcome to the hearth.
With your discription it sounds like the auger operation is very sporadic. You could test the output of the control board board with a multimeter when the timer clicks. but i would lean twards the board is on its way out or has a weak solder joint someplace. Just because it is so sporadic and you have replaced or tesed everything else
 

Johnny_I

New Member
Jan 20, 2018
5
CT
Thanks for the reply!

By control board, are you referring to the exterior block that contains the main power switch, burn rate dial and blower dial? Or the interior box with the two timer blocks?

If interior box, I replaced both timer blocks recently; system block last year and auger cycle timer last week.

If external, would you suspect its the main power switch or the burn rate dial? Adjusting the burn rate dial I do consistently hear the auger cycle timer block clicking at the appropriate intervals. It just doesn't seem to send power to the auger motor beyond that once the issue surfaces.

I'm baffled as to why the whole unit works great upon startup for at least 30 minutes (sometimes longer). If it were a bad burn rate dial i would think it would cause issues even while starting (<30m). It couldn't be a faulty convection snap disc, right? That would cut the blowers, too right? That's the only one of the three discs that if I shake it, it doesn't rattle.
 

Ssyko

Minister of Fire
Nov 6, 2017
3,006
Lorraine NY
Im at a loss without a good wiring diagram. I have another tech manual you can go trough and check out. It covers 93 and up I believe.

http://kirklandfireplace.com/TechInfo/Manuals/Pellet_Troubleshooting_Guide.pdf

The snap disc’s are the System snap disc (no documentation on this disc). The next is the Convection snap disc (i believe is low limit, pof) it turns the convection blower on when stove reaches temperature. Last is the Hopper snap disc it shuts the auger down if the hopper reaches an unsafe temp (high limt disc)
 
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nailed_nailer

Minister of Fire
Oct 29, 2007
938
Cape Cod, Ma
Just a guess here (not familiar with your stove) but have you looked at your exhaust vacuum?
Is your vacuum line plugged up or cruddy?
Most pellet feed issues circle back to a bad auger motor or vacuum switch. Unless there is a main board control problem.
---Nailer---
 

Johnny_I

New Member
Jan 20, 2018
5
CT
Nailed_nailer: The vacuum switch (flow switch) wires are currently tethered, bypassing the device until I can find the culprit.

Ssyko: I don't think it's the hopper snap disc, since I put new leads on those wires and hooked them up to a jumper temporarily once the auger stopped turning, and the issue persisted.

I originally though it might be the old auger cycle timer, since I was hearing it click at the appropriate intervals. I bought a replacement auger cycle timer with the exact same part #, and upon hooking up the leads to the same posts, it would give me a completely different experience; there was no regularity between cycles, completely random. The old/original cycle timer would at least click at a perfectly synced interval. Given this, I was skeptical that it could be the burn rate dial since my understanding is this dial merely controls the pause between motor turns, and that it's the cycle timer than controls how long to turn the motor for with each cycle (set to 2.5s).

Perhaps it is the burn rate dial; only emitting enough voltage to click the original timer block yet not strong enough to consistently send power through the new one (?).

I'll try and track down another burn rate dial. Does anyone have any good references for replacement burn rate dials?

Also, just looking to confirm, of the three snap discs (system, convection, hopper), only the convection doesn't make a slight rattling noise when shaken. Is that expected? And could a faulty convection snap disc (3yr old) cause an issue with the auger while not causing any issues with the convection blower itself?

Lots of questions, sorry. Thanks a lot for sticking with me!
 

Johnny_I

New Member
Jan 20, 2018
5
CT
Alright. I'm at my wit's end.

Brand new auger motor (2wks old), brand new components in control box (soldered in new burn rate dial, replaced power and toggle switches today), brand new auger cycle timer (last week), brand new system timer block (late last season). New disconnects on all wires.

Snap discs are about 2-3 years old. Convection snap disc turns the convection blower on at the appropriate time.

Auger turns fine for a few minutes, then you start to hear some squelching as the power is being sent to the auger for a few cycles, then the auger just stops turning. I do hear the cycle timer block still clicking at the appropriate interval. If I stop the entire system, wait for it to cool then fire it back up, auger turns fine again for a while (which leads me to believe it's not a jam or bearing issue). Note that the exhaust flow (vaccuum) switch is still being bypassed by jumping it's wires, so its not that, either.

I even tried jumping the hopper snap disc. The only two things I haven't swapped is the system snap disc (only ~3yrs old), and a complete rewire. Could these symptoms possibly be caused by a faulty system snap disc (three wire)????

BTW there are only about 64oz of pellets in the hopper, and it was vacuumed clean before filling.

Anyone know a good exorcist??
 

Ssyko

Minister of Fire
Nov 6, 2017
3,006
Lorraine NY
Well in this case, if it were my stove i would take all the safety devices ( temporarily ) out of the equation jump all your snap disc’s and vac switch and hit start. If it works plug 1 at a time in till it fails again. New augers can be bad, as it warms up from use the coil could have a short. If it still don’t function properly it’s gonna be the control board.
 
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Johnny_I

New Member
Jan 20, 2018
5
CT
Ssyko, I bypassed all safety devices, and no luck.

Here's what's weird, and there has to be a clue in here somewhere:

With the original auger cycle timer installed in the control box, I can hear it click at the appropriate interval set by the burn rate dial. It is consistent with every single cycle, and adjusts the delay appropriately depending on where I turn the burn rate dial. Problem is, while it clicks at the proper interval, its not sending power out to the motor consistently (and now not at all). As previously mentioned, the auger would power for a while then stop entirely (despite still clicking when appropriate). Consistent delay, inconsistent powering of motor.

With the new auger cycle timer (same manufacturer and part #) installed in the control box, it clicks at completely random intervals, and if I turn the burn rate dial anywhere below the max, it's even more of a crap shoot. HOWEVER, with this timer it actually turns the motor whenever it does click. It does not, however click consistently. Inconsistent delay, consistent powering of motor.

So to recap, the old timer block clicks consistently but doesn't power motor upon each click. New timer block clicks inconsistently but does power motor upon each click.

Another oddity. With the new timer block installed, if it doesn't turn for a little while and I get up from the couch and touch the stove, I get a static shock, and the motor turns immediately.

Could it possibly be a bad ground???

The only device I see with a ground wire is the exhaust blower which I had recently disconnected to clean it, but it was reconnected and tight. Also we don't use the igniter so those leads coming out of the harness are just loose with disconnects. I do feel voltage in those wires though. Should they be tethered if they are not hooked up to the igniter??
 
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Ssyko

Minister of Fire
Nov 6, 2017
3,006
Lorraine NY
Without having the boards in front of me and a few hours tracing the circuits, a wiring diagram of the stove.its all guess work. Can you post clear photos of both sides of the board or boards? If it is all 120vac circuits the ground would be the common. Very odd that a static charge would start a motor. Honestly i would search for replacement. You have way to much going on with that board