Is Your Toilet Running Up Your Water Bill?

How to save water—and money—by detecting and fixing leaks

By Mary H.J. Farrell

Updated March 18, 2019

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Water leak

Next time you get your water bill, take a look at how much water you’re using. If it’s more than 12,000 gallons a month for a family of four, you have some serious leaks.

That means you’re paying for water that’s going right down the drain. To stem the tide, the Environmental Protection Agency recommends checking your home for the most common causes of leaks during its annual Fix a Leak Week.

Before looking for individual leaks, check your overall water usage by monitoring your water meter over a 2-hour period when no water is being used.

Does the meter keep inching up? The good news is that many common leaks are easy and inexpensive to fix.

Where to Look for Leaks

Toilet leaks. Typically, toilets begin leaking when the toilet flapper or valve seal becomes old or worn out. A good way to check is to put some food coloring in the toilet tank and wait 15 minutes to see whether color shows up in the toilet bowl. If it does, you’ll need to fix the flapper or valve seal. You can probably find the replacement part at your hardware store, but to be sure, take the old part with you for comparison.

If the leaky toilet is old, consider replacing the whole fixture. You can get a new water-efficient one for as little as $100. “Older toilets can use four times more water per flush,” says John Banta, who oversees Consumer Reports’ toilet tests. “New toilets use as little as 1.28 gallons per flush, so replacing an older toilet can dramatically reduce your water bill.”

Find water-saving toilets in Consumer Reports’ toilet ratings; see below for a selection of top-rated toilets.

Faucet leaks. Old and worn washers and gaskets are frequently the cause of faucet leaks. If you attempt to fix the leak yourself, remember to turn the water off under the sink before you begin. You should also close the drain and cover the bottom of the sink or bathtub with a cloth, so you don’t lose any of the small parts. You can find quick how-to videos on YouTube.

Showerhead leaks. Some leaky showerheads are easy to fix, while others may need professional attention. Make sure there is a tight connection between the showerhead and the pipe stem. You can use pipe tape, also called Teflon tape, to secure it. You may also need to replace the washer. If you suspect a valve leak, it’s time to call the plumber.

Outdoor leaks. Check your garden hose for leaks at the connection to the spigot. If it leaks, try replacing the washer to ensure a tight connection to the spigot. You can also use a wrench and pipe tape. If you have in-ground irrigation, check to make sure it wasn’t damaged by frost or freezing over the winter. If it leaks, it may require professional attention.

Suspected leaks. If you see signs of moisture or mold on your walls, ceilings, or floors or you notice a musty smell, you may have a leak. Pipes could be leaking behind the walls, which requires the help of a professional plumber.

If any of your fixtures need replacing, look for the WaterSense label. Products with the label are independently certified to use at least 20 percent less water and perform as well as or better than standard models. In addition to toilets, WaterSense products include bathroom faucets, showerheads, and some irrigation controls.

Some water districts offer rebates to residents who replace their old fixtures with WaterSense models. To find out whether yours does, check the WaterSense Rebate Finder.

Top-Performing Toilets Under $250

How to Fix Leaks in Your House

Small leaks around your house could be costing you big on your water bill. Many of those leaks are easy and inexpensive to fix. On the "Consumer 101" TV show, Consumer Reports expert John Galeotafiore shows you how.

Mary H.J. Farrell

As a senior editor at Consumer Reports for more than 15 years, Mary H.J. Farrell reported on all manner of vacuums and cookware, as well as microwaves, mixers, freezers, and fans. Starting in the mid-1990s, she held senior positions at People.com, MSNBC, and Ladies’ Home Journal. One of her earliest jobs was at Good Housekeeping.