AC air handler buzzing sounds. Do you hear a buzzing sound when you turn on the thermostat? The only thing that comes on in the house when you turn on the thermostat is the fan relay and fan in the air handler or furnace. Try switching the thermostat HEAT/COOL switch to OFF. Then switch the fan switch from AUTO to ON. The fan (only) should come on. If the air handler makes a buzzing sound, it probably has a bad fan relay or, more likely, blower fan.
Installation—Having your HVAC systems installed by a professional is extremely important to prevent any future problems or needless repairs. Our professionals at Service Experts Heating & Air Conditioning can also help you choose what size equipment is appropriate for your house. Selecting a system that is too large or small can impact efficiency and add to your energy bills.