How to Troubleshoot a Pump Motor Squeaking before Shutting Down on a Gas Boiler Furnace

Gas Boiler Operation

• A gas boiler furnace uses water to carry heat to radiators or baseboard registers situated throughout a home. Like other furnace types, gas boiler furnaces are controlled by thermostats that respond to temperature changes in the building. Water that is heated at the bottom of the boiler tank rises to the top. The tank's circulator pump moves the heated water to the top more quickly, and forces the hot water through pipes to reach baseboard and radiator units.

Circulator Pump

• A circulator pump's motor includes a rotor, bearings and the wiring that delivers power to the pump. Squeaking or squealing noises made by a circulator pump may indicate problems inside the motor. Over time, the metal materials that make up the pump's rotor and bearings suffer wear and tear. Chemical reactions between metal and oxygen can corrode the rotor device. Mineral residues can form on rotor surfaces.

Bearing Problems

• The pump motor contains bearing components that enable the rotors to turn, circulating water within the tank. If the bearings are worn or have residue buildup, they may spin unevenly inside their tracks, which can cause a squeaking sound. The circulator pump can still run, though with little to no rotor movement. Hot water circulates through the tank more slowly, so heating system pipes may show little temperature change when the gas boiler furnace kicks on. Over time, considerable damage to ball bearing components can cause the motor to shut down after squeaking noises occur.

Considerations

• When a boiler pump motor starts shutting down soon after turning on, it may be time to replace the pump. The squeaking noise alone indicates bearing damage is taking place as bearings rub against metal surfaces. In some cases, the pump motor may resume normal operation after the motor assembly is oiled. Some circulator pumps require regular oiling to keep moving parts running smoothly. Check the manufacturer’s specifications on oiling needs.