I have a Trane furnace.I put up a new Non-programmable thermostat.I can make it call for heat nothing happens ,make it call forcool nothing happens.But if I turn the thermostat up and turn from auto to on the main blower comes on ,but will go off when I turn it off. The strange thing is when I turn the thermostat off and push the door switch I get a humming noise from behind thebox where the control boardis mounted.Any ideas