Keep an Ear Out for These Heater and A/C Noises

 In Keeping Cool, Staying Warm, System Maintenance, System Repair, Winter Topics

A funny noise coming from your heater or air conditioner can sound like alarm bells to homeowners who rely on these systems to keep their homes comfortable. Some noises are normal, like the comforting hum of a perfectly functioning unit, or some clicking and tapping noises as the unit kicks on or warm or cool air courses through the ductwork. But some noises need to be addressed immediately. Here are some heater and a/c noises to keep an ear open for in your home.


Your heater or air conditioner, either inside or out, shouldn’t be banging. That’s usually a sign that there’s a broken part or that something is improperly balanced. Either way, there’s probably a repair in your future, and that repair should be done by a professional.


Sometimes, clanking from the outside unit may mean that something, like a stick or twig, has fallen into the fan area. You need to remove it before it can cause damage. It could also mean that something has come loose or is out of balance and is hitting other parts, causing damage. Either way, turn the unit off, check for damage or debris, and call a technician.


Some clicking is normal as electrical components shut on and off and as air moves through the system. Consistent clicking, however, could mean your thermostat is trying to quit. Have a technician check as soon as you can.


Buzzing can mean lots of things. Much depends on where the buzzing is coming from. If it’s from the outdoor unit, it could be debris again, or it could be a more serious problem, such as a bad fan motor, loose fan blades or a bad blower. All of those things should be checked by a professional. A complete failure of something such as a loose fan blade can cause a lot more damage if it happens while the unit is running.


Even the best and newest units usually produce a low hum when they’re operating. However, a hum that you’ve never noticed before might mean that there are some loose parts or piping. Humming a/c noises can also come from electrical problems. If there’s humming and the compressor won’t start, that may be a more serious issue. Have a technician check on your heater or air conditioner as soon as possible.

Chattering or Rattling

Here’s our old friend debris again. Anything that’s fallen into the outside unit should be removed — and a cleaning should be part of your maintenance routine. However, chattering noises can also mean an electrical failure or loose parts in the fan. Look for loose screws or bolts in the outside unit’s casing. A great time to do this is when you’re removing it to clean it out.


If you hear high-pitched whistling or screaming, turn your heater or air conditioner off and call your service provider immediately. This can indicate either a refrigerant leak, which can cause a lot of damage and be dangerous to your health, or high internal pressure in your compressor, another dangerous situation. If you’re air conditioner or heater is making this noise and then immediately turns off, don’t try to turn it on. A sensor in the system has detected the problem and is doing its best to keep you safe. Squealing heater or a/c noises can also indicate a loose or bad belt, which should be repaired before it breaks and causes more damage.

No matter what noise your heating and air system is making, Barineau Heating and Air can figure it out for you. Schedule an appointment today.

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