Your toilet won't stop running — here's the fix
A toilet that keeps running is nearly always one of two cheap parts: a worn flapper (water leaks from the tank into the bowl) or a fill valve that won't shut off (water runs down the overflow tube). Both are inexpensive, no-solder DIY fixes. A running toilet can waste a large amount of water and quietly raise your bill, so it's worth fixing promptly — no safety gate needed.
Flapper or fill valve? A 30-second test
Take the tank lid off and look. If water is trickling over the top of the tall overflow tube, the fill valve isn't shutting off — adjust the float down, and if that doesn't hold, replace the fill valve. If the water level is below the overflow but the tank slowly empties and refills on its own (ghost flushing), the flapper isn't sealing — replace it.
Add a few drops of food coloring to the tank and wait 10 minutes without flushing; if color appears in the bowl, the flapper is leaking.
What it's costing you
A silently running toilet is one of the biggest hidden water wasters in a home and can add noticeably to a monthly bill. A flapper or fill valve costs only a few dollars; a plumber call for the same job runs an estimated $150–$400 (industry estimate). This is a strong DIY-first candidate.
When to call a professional
- • Water keeps running after you've replaced both the flapper and fill valve.
- • The tank or supply line leaks onto the floor, or the shutoff valve won't close.
Common questions
- Do I need to turn off the water?
- For a flapper or fill-valve swap, yes — shut the supply valve at the wall behind the toilet, then flush to empty the tank. It's a simple, low-risk job.
- The chain keeps getting stuck — is that the problem?
- Often, yes. A chain that's too long can slip under the flapper and hold it open. Shorten it so there's just a little slack.
Sources
- Running/leaky toilet repair: $150–$400 (US, industry estimate). Tier 3 (industry estimate)estimate · has commercial bias
HomeGuide · verified 2026-07-26