Dec 18, 2017 · Your boiler’s circulating pump moves the heated water from the boiler to the radiator and back again. If it is set too fast for the system, then you will notice vibrations and a loud humming noise. To check for this, look for the circulating pump and check its speed settings. Then, reduce the speed and see if that stops the humming noise. 3 Ton Ac Unit With Gas Furnace
Gas turns on; House blower turns on; The problem we had was the inducer fan in our furnace would cut in and out between step 1 and step 4. Most often, it would cut out right as the gas valve opened. This would correctly cause the inducer pressure switch to shutdown the furnace (the pressure switch is a safety mechanism).