Fan running constantly. Upon arrival the unit was found to be turned off at the thermostat but the fan could be heard running through the vents. The unit was opened up and the blower motor was turned off but a fan noise could be heard in the ductwork. The ductwork was traced back to the vent that was noisiest and a inline fan was found in the metal ductwork. The fan was unwired and the wiring was capped off. Unit is heating properly at this time.