Most house noises are harmless. Metal ducts pop as they warm up and cool down, and a water heater crackles as it heats. Some sounds, though, point to a problem that gets worse or more expensive if you ignore it: a squealing furnace motor, pipes that bang when a faucet shuts off, a toilet that gurgles, or an outlet that buzzes. Here is what common house noises mean and when to call a professional.
Heating System Noises
Fall is when many homeowners first notice new sounds, because the heat comes on after months of sitting idle.
Popping, ticking or groaning in the ducts
Metal ductwork expands as warm air moves through it and contracts as it cools. That movement makes popping, ticking and groaning sounds, especially when the furnace starts and stops. It is normal. If the sound is loud and happens every cycle, a technician can check for loose or undersized ductwork.
Squeaking or squealing
Squeaks and squeals from the furnace often come from dried-out motor bearings or a worn part. Left alone, either one can lead to motor failure.
Knocking, rattling or clanking
Knocking inside the furnace can mean the blower fan is hitting its housing. Clanking can come from rusted or loose parts. Have either one checked before it damages the system.
Banging or booming when the burners light
A bang or boom when the furnace starts usually means delayed ignition: gas builds up before it lights. That stresses the heat exchanger and should be inspected. See the warning signs of a failing furnace.
Whistling
A whistle from the furnace or the vents is often a dirty air filter restricting airflow. Check the filter every month, and clean or replace it when it is dirty.
Water Heater Noises
Popping, crackling or rumbling from a tank water heater usually means sediment has settled on the bottom of the tank. Water trapped under the sediment boils and escapes as the tank heats. A gas water heater can also make a soft pop when the burner lights. Draining sediment regularly helps. Rheem suggests draining a few quarts from the tank every month. See the water heater troubleshooting guide and why water heaters leak or burst.
Plumbing Noises
Banging pipes when a faucet shuts off
When a faucet, toilet fill valve or washing machine valve closes quickly, the moving water stops suddenly and the pressure surge makes the pipes bang. This is called water hammer. The sound can travel, so it doesn’t have to happen near the fixture. Loose pipe straps and high water pressure make it worse. A plumber can secure loose pipes, install water hammer arrestors and check your water pressure.
Clanging radiator pipes
The pipes that serve a radiator also drain water from it. If they are not draining properly, you may hear loud clanging, as if someone were hitting the inside of the pipe with a metal object.
A gurgling toilet or drain
Gurgling or bubbling when you flush or run water means air is trapped in the plumbing. A clog in a single drain can cause it. If several drains gurgle or run slowly, the problem is often a blockage in the main sewer line, such as tree roots or wipes caught on roots. See sewer and drain line inspections.
A toilet that runs on its own
A toilet that refills or runs when no one has flushed usually has a worn flapper or fill valve. According to the EPA’s WaterSense program, an old or worn flapper can make a toilet flush on its own or silently leak thousands of gallons a year.
Electrical Noises
Buzzing, crackling or sizzling
Outlets, switches and electrical panels should be silent. Buzzing, crackling or sizzling can mean a loose connection or arcing, which can start a fire. Stop using the outlet or switch and call an electrician. Learn more about electrical arcing.
A breaker that keeps tripping
A breaker that trips again and again is a warning, not a nuisance. See what causes circuit breakers to trip.
Air Conditioner Noises
Grinding, squealing or loud rattling from an air conditioner calls for service. See AC troubleshooting for the common causes.
Whistling Windows and Doors
A whistling window usually means air is moving in and out of the house. Improper installation, damaged weather stripping, temperature changes and ordinary wear can all cause it. The leak lets warm or cool air escape, so your heating and cooling system has to work harder to hold the indoor temperature.
A Smell, Not a Sound: Gas
If you smell rotten eggs or sulfur, you may have a gas leak. Leave the house and call your gas utility from outside.
House Noises FAQ
Why does my house make popping noises at night?
Most often it is metal ductwork expanding and contracting as the heat cycles on and off, or the house itself cooling after sunset. Popping that comes from the water heater usually means sediment in the tank.
Why do my pipes bang when I turn off a faucet?
That is water hammer. The water stops suddenly and the pressure surge shakes the pipes. A plumber can secure loose pipes, install water hammer arrestors and check your water pressure.
Is a buzzing outlet dangerous?
It can be. Buzzing or crackling can mean a loose connection or arcing. Stop using the outlet and have an electrician check it.
Why is my toilet gurgling?
Air is trapped in the plumbing, often from a clog. If several drains gurgle or drain slowly, the main sewer line may be blocked.
Call Central Heating Cooling Plumbing Electrical
If a sound in your home has you wondering, our heating, plumbing and electrical technicians can find the cause. We serve Kalispell, Whitefish, Bigfork, Columbia Falls and the rest of the Flathead Valley. Your Comfort Is Our Central Concern. Call 406-756-6656 for all your heating, cooling, plumbing, electrical and drain cleaning needs.
