Can I fix a running toilet myself? Cistern washers by state

A toilet that keeps running, trickling into the bowl or refilling on its own wastes a surprising amount of water. Nine times out of ten the cause is a worn washer or seal inside the cistern, a cheap part. Whether you can replace it yourself depends on where you live.

The rules by state

State	Replace washers inside a toilet cistern	Replace the whole toilet
Queensland	DIY OK	Licensed plumber
Western Australia	DIY OK	Licensed plumber
Other states and territories	Treat as licensed unless your regulator confirms	Licensed plumber

• Queensland: the QBCC’s list of unregulated work includes repairing or replacing the drop-valve washer, float-valve washer or suction-cup rubber in a toilet cistern.
• Western Australia: owners can replace a cistern washer.
• Everywhere else: we couldn’t confirm an exemption from the regulator. Ask them, or call a plumber.

Working out what’s wrong

Lift the cistern lid (it’s heavy and breakable, so put it somewhere soft) and watch a flush:

• Water keeps trickling into the bowl: the seal at the bottom of the cistern (the drop-valve washer or outlet seal) isn’t sealing.
• The cistern fills and water runs into the overflow: the inlet valve (float valve) isn’t shutting off.
• The flush button sticks or needs jiggling: the button mechanism may just need adjusting.

Replacing a cistern washer (Queensland and WA)

1. Turn off the water at the isolation tap near the toilet.
2. Flush to empty the cistern.
3. Take a photo of how everything sits, then remove the part with the worn washer.
4. Take the old washer to the hardware store to match it. Cistern brands use different parts.
5. Fit the new washer, reassemble, turn the water on slowly and check the cistern fills and stops.

If it still runs, or the valve is cracked or corroded, replacing the valve mechanism may be the fix. Check whether that’s covered where you live, or call a plumber.

When to call a plumber

• Leaks at the base of the toilet or from the pipes behind it
• A cracked cistern or pan
• Replacing the whole toilet suite, see can I replace a toilet myself?
• Any job outside what your state lets owners do

Sources

Every rule on this page is taken from these official sources. If a rule has changed, please tell us and we’ll fix it.

1. QBCC, Unregulated plumbing guide
2. WA Government, New plumbing rules for industry and homeowners

This guide is general information, not legal or professional advice. Rules differ between states, councils and individual properties, and they change. Confirm with your state regulator or council before starting work, and if in doubt, get a licensed tradesperson.