A toilet that keeps running, hisses, or refills by itself every so often is one of the biggest hidden water wasters in a home. It can add hundreds of rand to a municipal water bill, so it's worth fixing quickly. Most causes are cheap parts.
First, take the lid off the cistern
Look at the water level while the toilet is still.
- Water flowing into the overflow pipe (the open tube in the middle): the inlet valve (ball valve or float valve) isn't shutting off, or it's set too high.
- Water level fine, but the bowl keeps trickling: the flush valve seal or flapper at the bottom of the cistern is leaking.
- Refills on its own every few minutes or hours ("phantom flush"): almost always a leaking flush valve seal.
The food colouring test confirms a leaking seal: put a few drops in the cistern, don't flush, and check the bowl after 15 minutes. See also testing for a hidden leak with your water meter.
Simple fixes
- Adjust the float so the water stops about 2–3 cm below the top of the overflow pipe.
- Clean the seal. Turn off the stopcock behind the toilet, flush, then wipe grit and scale off the rubber seal and its seat.
- Replace the seal or washer. These are cheap and available at most hardware stores. Take the old one with you to match it.
- Replace the inlet valve if it keeps sticking or hisses. Modern valves are quieter and shut off more reliably.
When to call a plumber
- The stopcock behind the toilet is seized or leaking. Don't force it.
- Water is leaking at the base of the toilet or onto the floor.
- The cistern or pan is cracked.
- You've replaced the parts and it still runs.
For costs, see plumber prices in Benoni, or request quotes from local plumbers below.