What Causes the Central Heating Unit to Make a Loud Rattling Noise?

Central heating is a complex system that uses several different components to exchange heat back and forth in the air. The primary medium is the refrigerant gas, but the system also needs motors, fans, compressors, evaporators and other devices to control the refrigerant and channel it in the proper directions. With so many components, central heating systems can develop several problems that can create rattling and banging noises.

Panel Noises

Panels are the covers on the various devices that the heating unit uses, including the fan, the ductwork and the compressor. Eventually, panels can loosen as the screws wear down. These loose panels respond to the vibration caused by the motor and other movement and start rattling. Homeowners can quiet the rattling by refastening the screws on the panels.

Motor Noises

As central heating systems age, their motors start to wear out and the fans begin to collect grime and dust. The belts stretch and become displaced. All these changes cause the motor to make a lot of noise, which often sounds like rattles and loud vibrations. Homeowners can eliminate the noises by inspecting all parts of the motor for wear and replacing necessary components.

Heat Exchanger Problems

The heat exchanger consists of the coils and pipes that channel refrigerant close to the air where the heat can pass back and forth from the system. If the heat exchanger develops a crack, it cannot process heat correctly and will shudder or bang as it expands.

Sputtering Fuel

In a worst case scenario, a heating unit that uses oil can spill oil on the bottom of the ignition compartment. The oil ignites and creates a rattling sound as it burns. In gas heaters, a gas regulator not working properly can create puffs of gas buildup that create small explosions. Both of these situations are very dangerous; deal with them immediately to avoid damage and serious health hazards.