Loud, persistent or unexplained noises in your heating system could mean a serious problem that needs to be tended to by an HVAC professional. In some cases, though, heating system noises may be nothing to worry about and can be easily fixed. Here are some of the more common heating system noises you may hear, along with some information on what causes them and what you can do about them.
Heating System Noises
Furnaces, heat pumps and boilers generally operate quietly and without excess noise from within the system. In most cases, the noisiest part of a heating system is the blower fans in the air handlers that move heated air into the ductwork and out into your home. Under certain circumstances, however, you may hear noises such as the following:
- Booms or pops: Any sound that resembles an explosion, such as a deep boom or sharp pop, could be a danger sign. These sounds can be caused by clogged, rusty or dirty burners that allow a quantity of gas to build up and then suddenly ignite inside your furnace, creating a small explosion. If the dirty burners allow larger amounts of gas to accumulate, the explosions could become serious enough to damage equipment or start a fire. Contact your HVAC repair professional immediately to have the burners cleaned and adjusted.
- Rattling: Rattling noises or sounds of metal on metal are usually the result of a loose component within the system. They can also be caused by a door, panel or access hatch that hasn’t been closed or secured properly. The normal vibrations of your heating system are enough to cause the loose parts to rattle against nearby components and cause the sound. Finding and tightening loose parts and properly closing doors and panels are the best solutions.
- Clicking or snapping: A faulty ignitor or flame sensor can generate clicking or snapping sounds within the heating system. Replacing these malfunctioning components should stop the noises.
- Squealing sounds: Loose belts or drive belts that are slipping can cause high-pitched squealing sounds. Belts that cause these noises are usually found on the blower motors. Moving parts that haven’t been properly lubricated can also make squealing noises that will probably get worse over time. Replace the belts and lubricate the parts to solve the problem.
- Grinding sounds: If the bearings in the blower motor are wearing out, they can produce a grinding sound. Blower motors that make these noises will usually have to be replaced to stop the sounds.
Duct System Noises
Heating system ductwork can also account for several types of heating system noises. The ductwork is the network of large pipes that carries heated air from your HVAC unit to the inside of your home. Some causes of ductwork noises include:
- Rattling, banging or tapping: These types of noises in the ductwork can be caused by loose sections of metal duct clanging together. Small animals or rodents inside the ducts may also be the culprit. Repair the loose duct sections and make sure there are no creatures living inside the ducts.
- Ticking and cracking: As warm air flows through the ductwork, the metal can expand and contract in response to changes in temperature. This movement of the ducts can cause ticking or cracking noises. In most cases, there’s not much that can be done to stop these noises, but keep in mind they are most likely nothing to be worried about.
- Whistling, roaring or hissing: Air leaks in the ductwork can produce these types of sounds. They usually occur when sections of ductwork become loose or when the seals at duct connections are broken. Keep in mind that air leaks in ducts can not only produce annoying sounds, but they can also drive your monthly heating bills up because of wasted air and energy. Have your HVAC professional inspect your ductwork, repair any leaks and reseal any connections that have opened.
- Other odd noises: Sometimes sounds from other parts of your home can echo through the ductwork and be heard farther down the duct network. If you hear odd noises in the ducts, make sure it’s not just a television, radio or conversation elsewhere in the house being amplified by the ducts.
For more than 35 years, Roberts Heating & Air Conditioning has served residential heating and cooling customers in Northbrook, Deerfield, Glenview and nearby northern Illinois communities. Contact us today for more information on heating system noises and what to do if your heating equipment starts making unexplained sounds.