How to Unblock a Toilet — 5 Proven Methods
A blocked toilet is almost always paper, wipes or a foreign object in the trap or first metre of soil pipe. Ninety-five percent clear with a proper plunger or drain snake. Here are the five methods ranked by success rate.
Step-by-step method
1. Flange plunger — 80% success rate
Use a flange plunger (the one with the rubber cup and inner sleeve) — not a sink plunger. Ensure water covers the plunger head. Ten firm plunges, straight up-and-down. Flush to test.
2. Hot water + washing-up liquid
Squirt half a bottle of washing-up liquid into the pan. Add 4–5 litres of hot (not boiling — porcelain cracks) water from waist height. Leave 20 minutes. The soap lubricates and the fall breaks up soft blockages.
3. Toilet auger (drain snake)
A 3ft toilet auger reaches into the trap and first bend. Feed it in, crank clockwise, hook or break up the blockage, withdraw. £15 from any trade merchant — a permanent kit for any household.
4. Enzyme cleaner (slow but safe)
For partial blockages that flush slowly. Overnight bio-enzyme treatment digests organic matter without damaging seals. Safer than caustic drain unblocker on old cast-iron soil pipes.
5. Rod the external inspection chamber
If all toilets and sinks back up together, the blockage is downstream in the soil stack or gully. Lift the manhole cover in your garden — if full of water, you need drain rods or a jet-vac. This is where a plumber earns their money.
Frequently asked questions
Should I use caustic soda to unblock a toilet?+
Only as a last resort. It works but damages rubber seals, wax rings and old cast iron. Enzyme cleaners are safer and equally effective given time.
Why does my toilet keep blocking?+
Usually flushable wipes (they are not flushable), too much paper, or a slope issue in the soil pipe (should fall 1:40). Investigate the soil run if blockages return within weeks.