🔧Written by a qualified plumbing and heating engineer·

Blocked toilet — how to unblock it

Free DIY guide — no sign-up required. written by a qualified plumbing and heating engineer.
DIY Friendly💷 £0£3010–30 min
Safety First
⚠️ Do not flush a blocked toilet more than once — you risk causing an overflow onto the floor.

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Most likely cause & what to check

1

Stop flushing immediately if the toilet is blocked — further flushes risk overflowing the pan.

2

Put on rubber gloves and lay old towels on the floor as a precaution.

3

Use a toilet plunger — place it firmly over the pan outlet at the bottom of the bowl to create a seal. Push and pull vigorously 10–15 times.

4

Try flushing — if water drains normally, the blockage has cleared. Repeat the plunging if not.

5

If plunging doesn't work, try a toilet auger (drain snake) — insert it into the pan outlet and rotate the handle to break up or retrieve the blockage.

6

Pour a bucket of warm water from waist height — the force can help shift a stubborn blockage.

7

If none of these work, the blockage may be in the underground soil stack or drain. Call a drainage company to jet-clear the drain.

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🛠 Tools & materials you may need

Toilet plungerRubber glovesOld towelsBucket

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Frequently asked questions

Can I use chemical drain unblocker in a toilet?

Standard drain gel is not suitable for toilet blockages as it can't reach the obstruction effectively. A plunger or auger is the correct tool.

My toilet has blocked and overflowed — what do I do?

Turn off the water supply to the toilet using the isolation valve on the pipe behind/beside the toilet. Mop up the water wearing gloves, then clear the blockage before turning the water back on.