How to Fix a Blocked Toilet: Safe DIY Steps

Published 2026-06-02 · Cambridge Plumbers

First, stop it overflowing

The big mistake is flushing again to see if it clears — that just adds more water to an already-full bowl and risks an overflow. Instead, take the lid off the cistern and push the flapper down if it's still filling, and wait. If the water level is high, let it drop before you start. Pop on some rubber gloves and lay down old towels.

The plunger technique that works

A proper flange plunger (the type with the extra rubber lip for toilets) beats a flat cup plunger every time. Make sure there's enough water in the bowl to cover the plunger head — add some if needed. Seat it over the outlet to get a good seal, then push down and pull up firmly and steadily for 15–20 seconds. The pull is as important as the push. Repeat a few times; most blockages shift with patience.

Hot water and dish soap

If the plunger alone won't do it, this old trick often helps: squirt a generous amount of dish soap into the bowl, then pour in a bucket of hot (not boiling) water from waist height. The soap lubricates and the warm water helps break down the blockage — give it 10–15 minutes, then try the plunger again. Never use boiling water, as it can crack the porcelain.

What NOT to do

• Don't keep flushing — you'll flood the floor
• Don't pour boiling water into the bowl — it can crack it
• Don't tip caustic drain chemicals down a toilet — they're harsh, often don't reach the blockage, and make it unpleasant for whoever clears it next
• Don't poke wire coat hangers in — you can scratch the porcelain or damage the trap

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