US Patent 9015898 Extraction cleaner with heat transfer

An extraction cleaner for cleaning a floor surface includes a liquid distribution system and a liquid recovery system. The liquid recovery system includes a motor, and a motor cooling air pathway provides cooling air to the motor and removes heated cooling air from the motor. A duct system delivers heated motor cooling air to a supply tank of the extraction cleaner to heat liquid contained therein, and also drains liquid from the supply tank away from the motor.