Toilet | Regional Water Providers Consortium


  • Toilet leaks waste more than water.

Toilet Leaks, Retrofits, and Replacements

Toilets are the main source of water use in the average home, so learning how to take care of your toilet can mean real water savings – it can also help keep your water and sewer bills in check. You can reduce the amount of water used by your home’s toilet(s) by checking for leaks at least twice a year and, when possible, upgrading to a high-efficiency toilet.


Check for leaks in your toilet tank

Leaking toilets can waste thousands of gallons of water a month, leading to higher water and sewer bills. Sometimes toilet leaks are easy to hear, but many times they can be silent, making them easy to miss.

Here’s how to check your toilet for leaks:

  1. Remove the toilet tank lid.
  2. Drop one dye tablet or 10 drops of food coloring into the tank. (Dye tablets are often available for free from local water providers).
  3. Put the lid back on. Do not flush.
  4. Wait 20 minutes.
  5.  Check your toilet bowl. If you see colored water, you have a leak. If not, you don't.


What to do if you find a toilet leak:

If you rent, let your landlord know that your toilet leaks right away. If you own your home, it is likely that you can fix your toilet for about five dollars by replacing its flapper valve (see how to do this with this video from our friends at Seattle Public Utilities). If you don’t feel comfortable doing this work yourself, you will need to hire a plumber to do it for you.


Watch these how-to videos to learn how to identify and fix common leaks at home:


Identifying Common Toilet Leaks

Fixing a Toilet Leak


Replacing your old toilet with a High Efficiency Toilet makes sense.

Older toilets can use 1.6, 3.5, 5, or even up to 7 gallons (!) of water with every flush. Replacing an older model toilet with a new high efficiency (HE) toilet that uses only 1.28 gallons per flush (GPF) can greatly decrease your household's total water usage. Here are some things to keep in mind:

  • If you decide to upgrade, look for the WaterSense logo (think Energy Star, but for water efficiency). To earn this label, toilets must meet rigorous criteria for performance and must use no more than 1.28 GPF. Only HE toilets that complete the third-party certification process can earn the WaterSense label.
  • HE toilets are widely available at home improvement and plumbing stores, and typically cost about $100 - $400 plus installation fees. The estimated payback time for a HE toilet typically ranges from half a year to five years depending on the cost of your toilet and your household's annual water and sewer costs. Use this website to find information on which toilets perform best.
  • Check with your water provider for rebates! You could receive anywhere from $40 - $100 off your purchase. If purchasing and installing a new toilet is not an option, you may still be able to save water by finding and fixing toilet leaks or retrofitting your toilet.


What about retrofitting older toilets?

In some cases, people can retrofit an older toilet (those that use 3.5 gallons of water per flush or more) so that it uses less water each time it flushes. Retrofitting can be accomplished using different methods to reduce the amount of water needed to fill the toilet tank. These methods are not recommended because, while they shrink the tank, they don’t shrink the bowl, leading to the risk of having to flush twice.

Blue fill cycle diverter on a white background

If purchasing or installing a new toilet is not an option, one of the easiest retrofits is installing something called a fill cycle diverter. The fill cycle diverter is a simple plastic device that directs more water to the tank and less to the bowl while they refill. This way the tank and bowl finish filling at roughly the same time and water isn’t wasted while one runs water while the other one fills. Once installed, a fill cycle diverter will save about half a gallon of water with each toilet flush. 


Retrofitting Your Toilet