A furnace can make a lot of noise for a variety of reasons, whether it’s a clogged air filter, a dirty pilot light or a faulty motor. Those who ask, “Why is my heater making so much noise?” will want to spend some time solving the problem.
Question : My oven is making loud rumbling noises and I don’t know what to do. Why is my oven suddenly making so much noise? Is it something I can fix myself or should I hire someone?
Answer : When trying to figure out “Why does my furnace make so much noise when it’s running?”, many homeowners find that it’s as simple as replacing a clogged air filter. But fixing the problem isn’t always that simple. A loud furnace may be caused by something more serious, such as a failing motor. Homeowners can assess some of these causes and remedy them themselves, but calling in a professional HVAC technician can ensure the problem is diagnosed correctly and handled in a timely manner.
Furnace making loud noises?
Maybe it’s time to call a professional. Get free, no-obligation project estimates from furnace repair contractors near you.
A furnace that makes a loud popping sound could be a sign of a dirty burner.
A furnace uses a burner that combines air and fuel to produce a flame that heats the air. This flame requires an ignition device to turn this air/fuel mixture into a flame. The igniter can be a pilot light or an electric igniter that creates a spark to burn the mixture.
When the burner becomes dirty, it may take longer for the igniter to burn the air/fuel mixture. If this happens, the air/fuel mixture can build up, making a loud popping sound when ignited. Unless a homeowner has experience with gas burners, cleaning a burner should be left to professionals. Otherwise, the home could be left with a gas leak, which can be quite serious.
A loud bang from a gas stove means that the air/fuel ratio may be unbalanced.
To work properly, the stove must have the correct air/fuel ratio so that the burners ignite without delay and heat the air as required. When the air/fuel ratio is not balanced, it can lead to delayed ignition, resulting in a loud bang when the fuel builds up. Adjusting the air/fuel ratio is not something a homeowner should attempt without training and experience. It can lead to excess gas in the home, which can cause several problems. It is important to call a licensed HVAC technician to assess and adjust the air-to-fuel ratio so the furnace operates properly without loud bangs.
A dirty pilot light can cause the boiler to make loud noises.
As with a dirty burner, a dirty pilot flame can interfere with burner ignition. If ignition is delayed, fuel can build up; when it finally ignites, it can cause a loud noise. When dirt builds up in the pilot light, the light may have trouble staying lit or may be too dim to ignite the fuel. Cleaning a dirty pilot light can be as simple as blowing air into the pilot light with a can of compressed air. However, if this does not work, it will be necessary to call a technician who can disassemble the pilot light for cleaning.
Is your boiler making loud noises?
It may be time to call a professional. Get free, no-obligation project estimates from boiler repair services near you.
Clogged air filters can cause whistling noises.
Boiler air filters clean the air that the boiler draws in, heats and pumps into the home. When these filters become clogged, the furnace becomes inefficient and airflow is reduced. This can cause the furnace to emit a loud humming or whistling sound. Homeowners should change the furnace air filter regularly (every 1 to 3 months for 1- to 2-inch filters or every 6 to 9 months for 3- to 4-inch filters) to ensure that the system operates at maximum efficiency. If changing the filter does not prevent the boiler from emitting a loud humming noise, it is advisable to have a licensed HVAC professional examine the boiler.
Holes or joints in the ductwork can create unexpected noises.
The metal ducts installed to carry air from the furnace and air conditioner to the vents are designed to expand and contract: cold air will cause the material to contract and warm air will cause it to expand. As a result, when the furnace is first turned on after some time off, homeowners may hear unexpected noises as the warm air moves through the ducts. However, if these noises occur frequently or become louder, it may indicate that a part of the ductwork needs to be replaced. It is also possible that the joints or screws in the ducts are loose, causing unexpected noises as the air moves through.
A faulty motor can cause a noisy furnace.
Every furnace contains a blower motor that pushes hot air from the unit into the ductwork and throughout the house through the vents. If the blower motor belt begins to weaken, homeowners may hear an overly noisy furnace blower that squeaks or screeches. Replacing the belt may solve the problem, but it is not a task that homeowners want to perform themselves. Similarly, if the noise sounds like metal scraping on metal, it may indicate a more serious problem with the motor, such as a loose or broken fan wheel. If homeowners hear this noise, they should immediately turn off the furnace and call a professional technician to inspect it.
The problem may be as simple as a loose vent cap.
Vent caps can be found on the floor, walls or ceiling. If the vent cap is loose, it may rattle when air blows through it. The furnace may also make a loud noise when it shuts off – when air stops flowing through the loose vent cap, the cap may snap into place and make noise.
Using a screwdriver, homeowners can tighten the screws that hold the vent cap in place. It is important to tighten them just enough to keep the vent cover from rattling, but not too tight. There are many vent covers in the house, so homeowners may have to check them one at a time to find the one that is making noise.
A noisy furnace fan can be caused by a cracked heat exchanger.
Inside the furnace, the heat exchanger is the component that heats the air. When heat builds up due to poor airflow (think clogged air filters, dirty burners or a dirty pilot light), cracks can develop in the heat exchanger. When hot air hits these cracks, they expand and can produce loud noises. Although cracked heat exchangers are rare, if one is suspected, it should be repaired as soon as possible because it can release harmful gases such as carbon monoxide into the home. This inspection should be performed by an expert who can accurately diagnose the cause of a noisy furnace fan. A cracked heat exchanger usually means it’s time for a boiler replacement.
An HVAC technician can solve any problem related to a noisy furnace.
Some of the problems that cause furnace noise can be solved by the homeowner, such as replacing a clogged air filter or adjusting a loose vent cap. However, other problems, such as cleaning a dirty pilot light or adjusting the air-to-fuel ratio, may be more difficult to resolve. For any homeowner who is uncomfortable trying to diagnose a noisy boiler, whether your new boiler is noisier than your old one or you are trying to salvage a boiler that has been in the house for years, it is wise to seek the help of a licensed HVAC technician. These professionals are trained to work with a wide variety of heating systems and know how to assess problems such as a noisy boiler. Their expertise could save homeowners time and money on boiler costs in the long run.
