Home › Guides › Plumbing › How to fix a running toilet (the cheap DIY that saves water and money)
GuideA running toilet is the quiet money-waster of the home — it can waste thousands of litres and show up as a mysteriously high water bill. The good news: it's one of the most DIY-friendly plumbing fixes, usually a cheap part and ten minutes. Here's how to diagnose and fix it, and when to call in help.
A toilet that runs constantly or cycles on its own can waste an enormous amount of water — often the single biggest hidden driver of a high water bill. Beyond the cost, it's an easy fix to ignore until it's wasted hundreds of dollars. If you hear your toilet running or refilling when no one's used it, it's worth ten minutes now.
The flapper is the rubber seal at the bottom of the tank that lifts to flush and should seal afterward. Over time it warps or wears and stops sealing, letting water leak into the bowl so the tank keeps refilling. Replacing a flapper is cheap, universal and tool-free — it's the fix for the majority of running toilets.
Sometimes it's simpler than a part: a flush chain that's too long gets caught under the flapper and holds it open, while one that's too short stops it sealing — adjust for a little slack. A float set too high makes water run into the overflow tube continuously; lower it so the water stops below the overflow. Both are free, no-part fixes.
If the flapper, chain and float are fine but the toilet still runs or fills slowly, the fill valve (the tall assembly that refills the tank) may be worn. Fill valves are inexpensive and replaceable with basic tools — shut off the water at the valve behind the toilet, drain the tank, and swap it following the kit instructions.
Most running toilets are DIY. Book a plumber if the problem persists after replacing the flapper and fill valve, if there's a leak at the base of the toilet (water on the floor, not just in the tank), or if multiple fixtures have issues. A base leak in particular can damage your floor and needs proper attention.
If you'd rather not DIY, or the fix didn't hold, a plumber makes quick work of it. On Genie, plumbing is handled by licensed, insured pros at an upfront or quoted price, with payment held until it's done — a small job that stops a daily waste of water and money.
Every task in this guide is something you can book on Genie — vetted, insured pros at an upfront price:
Most often a worn flapper that no longer seals, letting water leak into the bowl so the tank keeps refilling. A tangled or wrong-length chain, a too-high float, or a worn fill valve are the other common causes — all cheap fixes.
It can be — a constantly running toilet wastes a lot of water and is a common cause of a surprisingly high water bill. Fixing it is usually a cheap part and ten minutes.
If replacing the flapper and fill valve doesn't fix it, if there's water leaking at the base of the toilet, or if multiple fixtures have problems. A base leak can damage your floor and needs a pro.
