As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FWD CABIN CONTROL RHEOSTAT NOT WORKING PROPERLY. VERY LITTLE HEAT IS PRODUCED UNTIL KNOB PASSES 4 O'CLOCK POSITION THEN ONCE HEAT IS INITIATED, IT RUNS TO FULL HOT. GROUNDED - YES. FOUND BOTH CABIN TEMP SENSOR FILTERS CLOGGED. CLEANED BOTH REF AMM 21-61-06. ADJUSTED TEMP UP AND DOWN, TEMP RESPONDS NORMALLY.