What was found
WHILE CLIMBING TO FL220, THE CABIN HEAT WAS TURNED UP. THE TEMP CONTROL KNOB WAS POSITIONED TO THE 6 O'CLOCK POSITION AS THE ACFT CLIMBED THROUGH 10,000 FT. WITHIN ONE MINUTE OR SO, THE FLIGHT CREW BEGAN TO NOTICE AN ODOR IN THE FLIGHT DECK. AFTER APPROX ONE MORE MINUTE, THE FLIGHT CREW OBSERVED SMOKE COMING OUT OF THE VENTILATION SYS. THE FLIGHT CREW IMMEDIATELY TURNED OFF THE HEAT. WHEN THE HEAT WAS TURNED OFF, THE SMOKE STOPPED.