Toilet Keeps Running? What’s Going On and How We Fix It

If you can hear your toilet refilling long after it’s been flushed, or water keeps trickling into the bowl, something inside the cistern isn’t sealing. A running toilet can waste a surprising amount of water without you noticing, so it’s worth sorting quickly.

How a toilet cistern works

Inside the cistern are two main parts. The inlet (filling) valve lets water in and shuts off when the cistern is full. The flush valve holds the water in until you press the button, then releases it into the pan. Most running toilets come down to one of these two parts.

Common causes of a running toilet

Worn flush valve seal

The rubber seal at the bottom of the flush valve can harden or warp over time. When it no longer seals, water trickles into the bowl constantly and the cistern keeps topping itself up.

Faulty inlet valve

If the inlet valve doesn’t shut off, the water level rises until it spills into the overflow. You’ll often hear a constant hiss or see a steady flow down the back of the bowl.

Sticking flush button

A button that doesn’t spring back fully can hold the flush valve open. Sometimes it’s the button mechanism itself, and sometimes it’s a misaligned connection inside the cistern.

Leaking cistern seal

On close-coupled toilets, a worn seal between the cistern and the pan can cause leaks onto the floor behind the toilet. This needs attention quickly, as water can damage flooring and the wall behind.

A quick check you can do

Lift the cistern lid (carefully, it’s heavy) and look at the water level. If water is flowing into the overflow pipe, the inlet valve is likely the problem. If the level looks normal but water keeps trickling into the bowl, it’s usually the flush valve seal. Avoid forcing parts or using chemical tablets as a fix, as they can damage seals further.

How we fix it

Our plumbers replace worn inlet valves, flush valves, buttons and cistern seals, usually in a single visit. If your cistern is old or parts are no longer made, we can supply and install a new cistern or a complete new toilet. You’ll get a clear, fixed quote before any work starts.

Toilet running, leaking or not flushing? Call The Plumbing Gang on 1300 671 525 or see our general plumbing services.