St Croix Prescott burning fine at first

[smithm]

I have a St. Croix Prescott pellet stove. which I have had for approx. 8 years. I love it. I had a few issues with blower motors but nothing else till now. I burn 3-4 tons per year. This year as long as I have it set to #3 it burns fine 24/7. The last cold spell we had last week I moved it to #4. It burns great all looks normal for approx. 1-1-1/2 hours and then the flame decreases the blower stays same speed. but even though its on #4 it runs like its on 1 or 2 setting. I never had this problem before. I called dealer were I purchased it and they though maybe it was the control board. I bought new one and replaced old one . Nothing changed same as old one. Has anyone else experienced this problem. I guess I should say when this happens it seems that there isn't any pellets coming but as fast as it does when I first start stove cold. I also though maybe it was the hi heat sensor, so I jumped it to bypass it to test it and it still has same problem. So I am not sure what to do next.

 

[Bioburner]

CSS IMO. sounds like the stove has some venting issues and needs a very good cleaning.
Hopefully someone with first hand knowledge with that stove model can chime in an give a few pointers on the trouble spots.
Welcome

 

[heat seeker]

Had a similar problem with mine. Turned out to be the auger motor bearings (bushings) needed oiling. The oil holes were not visible with the motor in the stove, and were located such that oil would have had to go uphill. A bit of oil, reinstalled the motor, and all was good. I found it by timing the RPM of the auger while running the auger motor. It was turning slowly, not the 2 RPM called for.

You can verify the control board by timing the on cycles of the auger motor and comparing to the chart in the manual.