Why a Furnace Makes Loud Noises When It Turns Off

A very simple reason that a homeowner may be hearing a banging sound when their furnace turns off is due to the inside filter.

Homeowners noticing a loud noise coming from their furnace when it turns off could be dealing with a simple concern. The noise may be described as a loud boom or bang and can be disconcerting, especially for the first time.

Below are some reasons for a banging sound coming from the furnace and how homeowners may be able to fix them.

Replace a dirty filter

A very simple reason that a homeowner may be hearing a banging sound when their furnace turns off is due to the inside filter. If the filter is dirty or was not installed correctly, air may not move through it efficiently, which will cause a backup. Once the furnace cycles off, the homeowner will hear a loud banging noise as the metal in the furnace expands due to the excess air. Regularly cleaning or replacing air filters prevents excess dirt from building up. If this does not help, contact a professional HVAC services company to investigate the cause.

Clean ductwork

Buildup in the ducts may also cause banging noises to occur. This buildup is much like the air filter buildup in that it causes air not to flow correctly and become trapped. A professional cleaning the ductwork thoroughly can reduce or eliminate loud noises.

Adjust the dampers

The loud noises could result from the natural expansion and contraction that happens as a system cycles on and off due to temperatures changing inside the ductwork. If this is the case, then adjusting the dampers on the side that supply airflow to the home to an open position can help with the noises. Open the dampers one at a time, then test to see what kind of difference it makes to the banging sounds.

Adjust the actuator

Adjusting the actuator in the system can sometimes eliminate noises from the furnace. An actuator works to help push the air through the system. Adjust the actuator up or down until there is a change in the banging sounds. Homeowners uncomfortable adjusting their actuators should contact a certified HVAC technician.

Clean the Fan

Another cause of noises coming from the furnace could be the fan used for both AC and heating and found within the ductwork. If this fan is dirty, it could easily be causing banging noises as it switches off. Cleaning this fan may remedy the loud noises.

Furnace repair services

Turn to a local, reliable furnace repair company for all furnace needs. They have the training to inspect, diagnose, and repair systems so homeowners don’t have to be uncomfortable in their homes.

A well-functioning furnace is a necessity during cold weather. Count on Evenflow Home Services for top-class services, including furnace installation, furnace repair, furnace replacement, furnace maintenance and tune-up, gas furnace repair, furnace gas valve, furnace capacitor, and furnace heat exchanger. Our technicians also offer emergency furnace repair.

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