How do I unblock a toilet?

The instinct when a toilet blocks is to flush again to push it through. That is precisely how bathrooms flood, because the cistern will happily deliver another six litres into a pan that cannot drain. Everything below assumes you have resisted that instinct.

Safety

What you'll need

• Flange plunger (not a flat sink plunger)
• Rubber gloves
• Old towels or newspaper for the floor
• Bucket
• Toilet auger / closet snake (optional)

Step by step

1. Stop flushing and lay towels around the base of the pan.If the pan is already near the rim, bail some water out into a bucket first.
2. Check the water level — you need enough to cover the plunger cup, but not near the rim.Too little water and you're compressing air; too much and you'll splash the room.
3. Insert the flange plunger so the rubber sleeve seats into the outlet.A flat sink plunger cannot seal a toilet outlet. This is the single most common reason plunging a toilet fails.
4. Push down slowly to expel air, then plunge with firm, steady strokes 15–20 times.Slow first stroke, then rhythm. Violent plunging splashes and achieves less.
5. Pull the plunger off sharply on the last stroke and see whether the level drops.A sudden drop means it's cleared. Wait and watch rather than immediately flushing.
6. Once the water drains, flush once and watch the level carefully.Be ready to close the isolation valve if it rises. Know where that valve is before you flush.
7. If plunging fails, feed a toilet auger into the outlet, cranking as you push.The auger's protective sleeve stops it scratching the ceramic. Ordinary drain snakes will mark the pan.

Tips

• A squirt of washing-up liquid and a bucket of hot (not boiling) water left for 15 minutes can soften an organic blockage enough for a plunger to finish the job.
• Boiling water can crack a ceramic pan through thermal shock. Hot from the tap is the safe limit.
• Blockages that recur in the same toilet often mean an obstruction further down or a partly collapsed drain — worth investigating rather than plunging monthly.
• Wet wipes, even ones labelled flushable, are the most common cause of stubborn toilet blockages. Bin them.

Common mistakes

• Flushing again to see if it clears — The cistern delivers another cistern-full into a pan that can't drain. This is how bathrooms flood.
• Using a flat sink plunger — It can't seal against a curved toilet outlet, so it generates almost no pressure where it's needed.
• Pouring boiling water into the pan — Thermal shock can crack the ceramic.
• Using a standard metal drain snake — It scratches the glaze permanently. A toilet auger has a sleeve for exactly this reason.

Questions people ask