Things That Go Bump in the Night (No, It’s Not a Ghost … Probably)


You’re just about to drift off to sleep, when suddenly there’s that strange thumping again. Your mind goes wild with the possibilities. Could it be wind? An animal trapped in the walls? Or perhaps a ghost?

Instead of hiding in the hall closet or bringing in an exorcist, you could try looking for more rational causes for those creaks, bangs, and thumps. But beware: You’ll want to investigate, pronto.

That’s because sometimes strange noises are simply nothing more than a house’s old bones creaking. But other times they’re a warning to prevent something really terrifying from happening—like a backed-up sewer line—or worse.

Here’s a look at what you need to know in order to understand what you’re hearing—and how you might be able to quiet your house without having to call in the pros.

Gurgling from the toilet

No, this is probably not the waking noises of a commode demon. Instead it could be one of two things, says Lev Moskovich, a plumber with SERVIZ in Sherman Oaks, CA:

1: A common cause is a worn-out toilet fill valve (the part of the toilet that controls refilling the tank after each flush).

2: More ominously, tree roots might have grown into the sewer pipes and a couple of baby wipes or sanitary items you accidentally flushed might have snagged on the roots, partly blocking the sewer line. That gurgling sound could be the plumbing equivalent of a ticking time bomb because you-know-what might be getting ready to hit the fan when that blocked pipe bursts.

“A professional might have to snake out the line or use a camera to inspect in this instance,” Moskovich says.

Silence the sound: Before calling in a plumber, Moskovich suggests a trip to your local home improvement center for a new gasket.

“Replacing a gasket is usually quick and easy and can take as little as 10 minutes,” Moskovich says.

Swapping out the old fill valve for a new one hasn’t silence the gurgling? OK, bite the bullet. Call a plumber.

Knocking or banging inside the walls

Yikes! Did you guys see any of the “Paranormal Activity” flicks? Or “Poltergeist”? This could be one seriously pissed-off spirit, or even a family of ’em.

Or, if the sound typically occurs when you turn your water faucets on and off, it’s more likely you’ve got a pressure hammer. It’s caused when air pressure builds up in your water pipes, causing them to vibrate when the pressure is released, says J.B. Sassano, president of Mr. Handyman in the Detroit area.

“If the pipe wasn’t mounted properly, or it has loosened over the years, that could also cause it to bang against the stud in your wall,” Sassano says. “However, water pressure is usually the primary cause.”

Vibrating pipes can cause the connections to come loose. And if that happens, water will leak inside the walls, ruining drywall and becoming a breeding ground for mold.

Silence the sound: “A water hammer arrester is a fairly inexpensive fix found at a hardware store,” Sassano says. “It helps prevent banging pipes, especially where pipes are exposed, such as at a washing machine.”

However, if the noisy pipes are inside walls, call in a pro to evaluate and diagnose the issue.

Hissing in the bathroom

Toilets are notoriously finicky. It’s not unusual for even a newly installed fixture to need some tweaking to quiet the hiss caused by a leaking flapper. The flapper—the connection point between the tank and the bowl—holds water in the tank, preventing it from entering the bowl until you flush.

“A leaky flapper causes the fill valve to turn on slightly, refilling the tank due to water loss,” Sassano says.

Silence the sound: Flushing the toilet is the first step to quiet the hiss. After the toilet bowl has completely refilled postflush, stand over the toilet to see if any water continues to enter the bowl, Sassano says. If so, the length of the flapper chain may need to be adjusted so it sits flush on the valve seat.

A more colorful approach to diagnosis? Flush the toilet, and once the bowl is completely refilled, add a few drops of food coloring in the tank. If any color starts to seep into the bowl, it’s time to replace your flapper, Sassano says.

Radiator pops and clicks

Expanding metal can sometimes sound like hissing and groaning. This happens because some loop systems that circulate hot water get air bubbles in them and need to be “bled” just like car brakes do, saysJames Walker, vice president of Aire Serv Heating & Air Conditioning.

Silence the sound: You can buy or make decorative boxes for radiators to cut down on the sound.

“But they may also reduce the amount of heat given off of the” radiator, Walker says.

You can try a radiator key or flat-head screwdriver (depending on the system’s valve) and slowly turn counterclockwise until water starts to drip out. That can release any trapped air and water bubbles and quiet the clunky radiator.

Bottom line: In nearly all instances, ignoring a strange house noise is never a good idea. Doing so can often lead to the need for a bigger, more costly repair at some point down the line, Sassano says. Plus, it could cost you a few precious nights of sleep, too.