Burning a Lot of Coal, Coal-Trol Gone Bad?

this is my second season with the pioneer/coal-trol combo. this year I am burning almost double per day with last years coal.
thermostat is 15 ft away from stove on an inside wall, a fan moves the heat towards the thermostat. my settings are set temp 74, min 5, max 44. when feed rate is at 99 I have approx 1" of ash at end of shute. power vent is turned down to 25%, bara damper (plumb and level) set at 3, manometer shows between .03 and .05.
when the thermostat calls for heat with a set point of 74 the room will heat to 75 but the coal feed will continue for at least 20 min. is this normal as I don't recall this happening last year? ie room temp 75 feed rate +89, five min later +89, 5 min later +85, 5 min later +83, 5 min later +80.

thank you

paul
mt top

Sounds like it is behaving normally, slowly backing off the feedrate if it is running a bit too hot.

thank you for the prompt reply

paul