Is My House Haunted? 3 Frightening Noises Your Plumbing May Be Making

By Mengning Heil

October 29, 2021

Plumbing Tips

Reading Time: 3 minutes

Is My House Haunted?

Does it ever sound like your house is haunted? Do you hear knocks in your wall, screeching in the night, and phantom flushes at random moments? It could be the case of spooooooky plumbing! Here are the three types of sounds your plumbing might make and why they could be happening.

is my house haunted

A Knocking Noise in the House Walls

Do you hear knocking, like a “tap, tap, tap” behind your walls? It’s probably the pipes expanding and hitting against the wood framing of the house. When hot or sometimes just regular water runs through pipes, the pipes expand and bend slightly, then straighten out. The expansion and contraction causes the pipes to rub up against the braces that hold them in place or knock against the wood that they are up against. Pay attention to when the knocking tends to happen. Is someone taking a shower or running the water when the knocking happens? It’s probably water running through pipes! If you want to stop the knocking sounds, you will need to secure the pipes securely to the frame of the house with braces. 

Knocking Noise in House Walls

House Vibration and Screeching in the Walls

If the sounds you hear in your house are more high-pitched or loud rumbling when the water is being used, you have a water pressure issue. The water coming into your house is highly pressurized. First, it must pass through the pressure reducing valve (aka PRV), next to your main water shut off valve. (We have previously explained how to find your emergency water shut off valve on the Heil Plumbing DMV blog.) If your PRV hasn’t been replaced in 20 or so years, it may be due to be replaced. The PRV is responsible for bringing down the pressure of the water to a level your fixtures can handle. If the pressure is too high, your fixtures, like your faucets, may be more prone to break. 

Another place where water pressure can be an issue is areas in the house where water is being shut off suddenly like near a washing machine and next to a check valve. If the pipes are having a challenging time handling the immediate changes in pressure when the water turns on and off, then it may cause a loud bang or rumble. A plumber can fix the issue by installing a hammer arrestor to absorb the shock of the water.

The Phantom Flush

Does your toilet flush on its own? When your toilet flushes randomly, also known as phantom flushing, you could have a leaking toilet. Your toilet will flush if the water in the tank is draining into the bowl. You may need to replace the toilet flapper.

Are you looking for an expert plumber in Gaithersburg, MD or the surrounding areas? Contact Heil Plumbing today. We offer a range of reliable plumbing services, including drain cleaning in Rockville and water heater repair in Jessup.


Heil Plumbing is a family-run company owned by a third-generation master plumber. We can help you with a full range of plumbing services, including toilet installation and repair, leak detection and pipe repair, faucet repair and installation, drain cleaning, and water heater repair in Montgomery County and the surrounding areas.