Tested heat and cool mode on the right hand side bard unit (facing the thermostat). Heat mode is operating without a loud noise. Right hand side thermostat was off and left side was on set on 64 heat. Tech believes the right hand side thermostat may have been left on cool mode and operated the compressor while the unit on the left was heating. Tech left both thermostats set on 68 heat and informed the customer to call us back if any abnormal noise is heard. Amp draw on blower motor and capacitor checked good. Bard unit#14. Bard units were recommended to be replaced during the last CmA due to reading bad windings on the compressors.