Quadrafire Contour Starts and dies out because it stops feeding pellets?

[Don2222]

Hello

Working on this Quad Contour. I did a little rewire because I did not like the fuse.
https://www.hearth.com/talk/threads/well-it-is-time-to-re-wire-this-old-aladdin-quadrafire.128671/

The stove fires and starts feeding pellets when the T-Stat terminals are jumped.

Tried cleaning the thermocouple cover but still did not work. Also changed control boxes and still did not work.

Could it be a bad thermocouple? Any good way to test? How many millivolts should it read with a flame present?

I heard if you pull the Thermocouple cover off and put a flame under it, then a meter should read 15 - 18 Millivolts?

See pics below. Click pics to enlarge:

 

[Don2222]

Ok, this is being a tough one, so we havee to roll up our sleves!
Luckily I have a good stove to compare this one to, so I pulled out the butane lighter and the Digital Multimeter with the Millivolt scale!
Also the stove under test did not have a TCouple support bracket so I made one.

It appears that a good TCouple goes from 0 to 18-22 millivolts DC

Stove issue
Stove starts, auger turns and feeds pellets during startup and pellets catch fire.
Then pellets stop feeding and fire dies out and stove shuts down.

Here is the diagnosis.
Checked all snap discs and vacuum switch. All test good. Also new wiring harness was installed to eliminate bad connections and installed correct fuse holder.
Lighting the TCouple tip, I could see the voltage rise from 0 to approx 22 milivolts DC on both stoves. Therefore TCouples seemed good.
Tried known good control box and still same problem.
Removed auger for service. Completely wire brushed cleaned, ground down a little pox and smoothed with emory coth.
Then used Dry Moly spray to protect and further smooth auger. Also lubed motor bearing with light weight machine oil.

Result of auger service.
Stove ran longer before it died and fire went out. Stove got hot and convection blower came on for the very first time.

Final test
Using molex to spade connector, plugged AC test cord into auger motor right after failure and motor still did not turn.

Summary
Auger motor heat failure. When stove heats up, the auger motor quits.

Could it be anything else? Any comments?

Pic 1 & 2 - Working Stove Testing ThermoCouple Near max DC output with tip engulfed in a flame
Pic 3 & 4 - Non working Stove Testing ThermoCouple Near max DC output with tip engulfed in a flame
Pic 5 - New Stainless Steel Burn Pot bolts. Old Bolts were worn!
Pic 6 - New SS Bo;ts and cleaned Thermocople with new support bracket.

 

[MountainSean]

Not at all unusual for that in Quad auger motors in my experience. Once they get hot they tend to lose some of their strength and as far as I can tell Quad has them engineered pretty close to tolerance so once they start to lose strength they stop feeding faster than a MK or GA auger motor would. Was there any grease leaking out of the motor anywhere? That is another sign I run into pretty often.

 

[Don2222]

Not at all unusual for that in Quad auger motors in my experience. Once they get hot they tend to lose some of their strength and as far as I can tell Quad has them engineered pretty close to tolerance so once they start to lose strength they stop feeding faster than a MK or GA auger motor would. Was there any grease leaking out of the motor anywhere? That is another sign I run into pretty often.

No grease. Thanks Sean for your experienced knowlegable help! Glad you concur with the findings!

 

[Don2222]

Right on Sean "the Auger Motor failed when hot" and Thanks

Works Perfect now - See pics of new auger motor and firebox new paint.