Friendly Reminder - If your Lennox-Whitfield Lites & dies -- clean your photo eye's lens - see pics

[Don2222]

Hello

After pressing On - The auger runs continuously and fills the burn pot with pellets, aand the exhaust blower runs pulling air over the ignitor as it heats up. When the burn pot fills up with pellets, the auger stops and waits for the pellets to light. After the pellets light the Photo eye must see the fire for the auger to start feeding intermittently during the normal run cycle. The on time is increased by raising the heat level.

Now if the photo eye cannot see the fire because the lens is dirty, the fire will die out and the stove will stop. Pressing the On/Off button will only bring the stove back to the beginning of the start cycle and feed alot more pellets to fill the burnpot again. The stove will still not stay running.

The manual states to take a small artist's paint brush and stick it up the chute from inside the fire box to clean the lens. I tried it with no success. The best way, is to pull the cover off the inside of the hopper and remove the bracket and the lens with the two nuts holdng it in. Then use a non abraisive glass cleaner with No Amonia to clean the lens.

The best test is to shine a flash light up the auger chute. If you can see the light clearly thru the lens it is clean and the stove will run normally.

See Page 28
(broken link removed to http://www.ncsg.org/wcmedia/documents/installationmanuals/whitfield_Profiles20FS-30FS-30INS.pdf)

Has anyone seen the above problem?

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Also the fan blades on the combustion fan was not turning freely so I replaced the blower. Taking the exhaust blower out and spinning the impeller blades by hand showed they stopped spinning abruptly. Even though the exhaust blower worked it was noisey.

I know if the combustion fan kicks on as soon as you plug it in that is a different issue. that issue you must unplug the photo eye from the board, then plug it in. If the combustion blower does not start then the photo eye is bad. If the exhaust blower still starts once plugged in, then the control board is bad. The AC voltage going to the exhaust blower from the control board can be checked with a multi-meter, There is quite a huge range on the voltages because the newer boards gave a lot of adjustment range for the control boards.
Start up: 75 volts
Low: 62 - 90
Medium: 70 - 101
High: 78 - 113

Specs are all +/- 5 volts.
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Pic 1 - Photo Eye bolted to inside cover next to auger chute. Remove two nuts from the cover and turn it over.
Pic 2 - Wipe dust off hopper side of lens with a Q-Tip and then remove both nuts to remove lens and support bracket.
Pic 3 - Light shines up auger drop chute and shows clean lens!
Pic 4 - Stove runs great!

 

[wwert]

Putting a photo eye in a pellet stove was a bad idea. That technology came from gas furnaces which burn clean and doesn't work well in dusty pellet stoves. I usually disconnect it and replace it with a POF disc mounted on the combustion fan.

 

[Don2222]

Putting a photo eye in a pellet stove was a bad idea. That technology came from gas furnaces which burn clean and doesn't work well in dusty pellet stoves. I usually disconnect it and replace it with a POF disc mounted on the combustion fan.

Agree 100 percent! Will a F-120 "close on rise" 3/4" snap disc work?
Which do you use? Air stream or surface mount?

 

[wwert]

Sorry didn't see your question. 140 degree POF, the white ceramic one sold by appliance and air on EBay. That's what whitfield used originally. Some stoves had the cutout on the combustion motor housing so that works great. Otherwise a surface mount should work but never tried it.