P68 - How To Measure Heat Output?

What is the best way to measure heat output on a P68?

It seems as though my stove is not putting out as much heat in the past.

Tried the basics : clean stove (including esp probe, vent, fines box, etc) Also various pellets, including the premium Cleanfire Pacific softwood.

I noticed at the beginning of the year, the fan sounded louder than I remembered. And before I could stand 4 feet away from the stove and feel as though I couldn't stand there more than a minute, but now I can even with fan set to high. Adjusting fan speed from high to medium doesn't have much of a sound difference, but from medium to low, there is.

Thanks
-Brian

DAKSY said:

Make sure the heat exchanger "accordion" is cleaned, both IN the top of the firebox & behind the vents above the door.
That's where the heated air comes from...
Scrape & brush the grooves in the firebox & brush & vacuum the vent holes through the front.

Click to expand...

Ya, I actually use my hands to force as the ash down. There is a lip above the door that has a ton of ash usually. Also, some ash can stick well to the actual exchangers. Never thought of the vent holes though - ill check them tonight.