Why Does My Toilet Make Noise When Not In Use?

Why Does My Toilet Make Noise When Not In Use?

Those loud sounds from your toilet can be baffling, to say the least. They seem to happen even though no one is using the toilet. There are many possible reasons for a noisy toilet: some aren’t so serious. They’re the ones you may be able to fix yourself, while others mean you need emergency plumbing repair RIGHT NOW.

So, why is my toilet making noise when not in use? It all depends on the type of sound that you’re hearing. Here are 5 everyday noises you might hear from your toilet and whether you should repair vs. replace your toilet.

Ghost Flushing

This is a common plumbing issue. Mysterious but true: sometimes your toilet makes noise and seems to flush itself. You’ll hear a sudden sound of running water, but no one’s in the bathroom. Could it be a ghost using the facilities? Well, actually, no. The phenomenon is caused by a slow toilet leak from your tank into the bowl. When the toilet tank level gets low enough, the water will be switched on automatically. This produces the eerie sound known as ghost flushing or your toilet making phantom flushing sounds.

WHAT TO DO: How do you fix ghost flushing? Most likely, replacing the toilet flapper (a fast, easy, and affordable fix) will “exorcise” the issue.

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Knocking/Banging – Loud Noise 

Bang! Bang! Bang! That loud knocking or banging sound — noticeable several minutes after a toilet flush — is not just annoying. It can be a sign of serious trouble with your water supply line, or plumbing due to overly high water pressure. “Water hammer” is an aptly named syndrome that occurs when there is a sudden shutoff of water flow when the toilet has refilled after flushing, and the fill valve closes too abruptly.

WHAT TO DO: Don’t ignore this loud sound. Water hammer may lead to major damage, such as burst pipes. Instead, install a water hammer arrestor on your toilet’s water line for more peaceful plumbing.


How much hissing is too much? A brief hiss post-flush as the tank fills is fine — that’s the usual sound of your toilet tank refilling. However, constant hissing means that the tank never stops refilling — and you’re wasting water. What’s the reason? Once again, it is probably due to a worn or faulty flapper. This allows water to leak slowly from the tank into the toilet bowl.

WHAT TO DO: Flapper replacement is the obvious solution to fixing this hissing sound. If that doesn’t help, though, you may have a faulty fill valve — which is a job for professional plumbing repair.

“TV Static” Sound – Potential Fill Valve Issues

Time to adjust your set … er, toilet. A TV static-like sound tends to be due to an incorrect setting for your toilet’s ballcock or water fill valve. Both serve to stop the water from running (and potentially overflowing) once your toilet has been refilled. However, if the fill valve has not been adjusted to the right level, excess water will continue to flow into the toilet and then noisily drain out through the overflow pipe.

WHAT TO DO: Adjust the ballcock and the fill valve correctly to be at a lower level than the overflow tube.

Gurgling Noise

A gurgling noise is one of the trickiest types of toilet noises to diagnose. This strange sound has so many potential causes! While gurgling usually indicates some blockage, the culprit could be a clog inside the toilet or a blocked vent stack or drain. It might even be a red flag that the sewer drain has broken or collapsed. A telltale sign is noticing a stinking smell coming from your toilet, even after cleaning it.

WHAT TO DO: Check in with your neighbours first. If they are also experiencing this same type of issue, their toilet is making noise, the reason is likely a problem with the municipal sewer line in your area. Call the city emergency line to report it. If the problem is only in your home, plunge or snake the toilet to dislodge the clog. If you don’t succeed, call a reliable plumber for skilled help.

We’ll Quiet Your Toilet Down

Call the expert plumbers at Dr HVAC to take care of strange noises or any other toilet replacement or repair you might need in the Greater Toronto Area. We’ll quiet down your plumbing and leave you with a toilet working properly, and peace of mind from any water leaks.