Blocked Toilet in London? Here's How to Unblock It -- and When to Call for Help
Most toilet blockages clear in under 20 minutes with the right method. This guide tells you exactly what to try and in what order.
Important -- Do Not Do This
- NEVER pour boiling water directly into a toilet bowl -- it can crack the porcelain.
- NEVER use chemical drain unblockers in a toilet -- they can damage seals and do not work on solid blockages.
Method 1 -- Most Effective
The Plunger (Start Here)
You need a toilet plunger (flange plunger) -- not a flat cup plunger. A flange plunger has a rubber skirt that extends into the drain opening and creates a proper seal. Cup plungers are for sinks, not toilets.
Put on rubber gloves
Toilet water may splash during plunging.
Add water if the bowl is low
You need enough water to fully submerge the plunger cup. Pour from a bucket if needed.
Position the plunger over the drain hole
Press firmly to create an airtight seal before you start. The flange must be inserted into the drain opening.
Push down slowly, then pull up sharply
Repeat 15-20 times. The pull stroke does as much work as the push -- don't rush it.
Flush to check
Stand back and flush. If water drains normally, the blockage has cleared.
Repeat up to 3 times if needed
Give each attempt 15-20 strokes before giving up and moving to the next method.
Method 2
Washing-Up Liquid and Warm Water
Works well for waste that is partially compacted or partially through the trap. The soap lubricates the blockage; the warm water adds weight to push it through.
Pour a generous squirt of washing-up liquid into the bowl -- more than you think you need.
Follow with a full bucket of warm (not hot) water, poured from waist height to create pressure.
Wait 5-10 minutes for the soap to work its way around the blockage and lubricate it.
Attempt to flush. If water drains away, repeat the flush once more to confirm clearance.
Method 3 -- When Plunger Has Failed
Drain Snake / Toilet Auger
Use this when the plunger has failed after 3 full attempts. A toilet auger reaches further into the drain run and can break up or retrieve blockages the plunger cannot shift.
How to use a toilet auger
- Feed the coil end into the toilet drain opening.
- Turn the handle clockwise as you push the coil forward.
- When you feel resistance, continue rotating to break up or hook the blockage.
- Pull back slowly while continuing to rotate to retrieve any material.
- Flush to confirm clearance.
Buying one
A toilet auger costs £15-£40 from B&Q or Amazon. Available for next-day delivery if you need it urgently.
Do not use a standard drain snake -- they lack rubber coating and will scratch or crack the porcelain. Only use a toilet auger with a rubber or plastic sleeve.
Causes
6 Reasons Toilets Block in London
Understanding the cause helps you pick the right fix and tells you when DIY isn't enough.
Wet wipes
London's biggest toilet blockage cause. 93% of sewer blockages involve wipes. Even 'flushable' wipes do not break down in water.
Toilet paper build-up
Too much paper flushed at once. Especially common in older low-flow WCs that don't generate enough flush force.
Foreign objects
Children's toys, phones, cotton buds, sanitary products. Plunger is largely ineffective for solid objects.
Shared drain blockage
All toilets or drains in the property are blocked simultaneously. Indicates a blockage in the shared drain run below the property.
Partial trap blockage
Waste is caught on the trap curve. Causes repeated partial blockages -- toilet flushes slowly and may back up on the second flush.
Faulty cistern (not flushing properly)
Cistern fills but the flush is too weak to clear the bowl. Not a blockage -- the cistern mechanism or fill valve has failed.
Stop DIY -- Get Help
When to Call a Plumber Immediately
The plunger has failed after 3 full attempts
Multiple toilets or drains are blocked at the same time (shared drain issue)
Sewage is coming up in the bath or shower drain
You can hear gurgling from other drains when you flush the toilet
Water rises to the bowl rim and does not recede after 10 minutes
Costs 2026
Unblocking a Toilet in London -- What It Costs
| Service | Cost | Duration |
|---|---|---|
| DIY (plunger) | Free | 5-20 min |
| Drain engineer (standard blockage) | £80-£150 | 30-60 min |
| Drain engineer (CCTV needed) | £150-£300 | 1-2 hrs |
| Drain rod clearance (external) | £100-£200 | 30-90 min |
| Cistern mechanism replacement | £80-£200 | 1-2 hrs |
| Emergency out-of-hours | £150-£300 | Same day |
All prices include VAT. Fixed quote given before any work starts.
Prevention
How to Stop Toilet Blockages Happening Again
Only flush the 3 Ps
- Pee
- Poo
- Paper (toilet paper only -- not tissues, not kitchen roll)
Never flush these
- Wet wipes (including "flushable")
- Cotton pads and cotton buds
- Sanitary products
- Hair (from brushes or shaving)
- Dental floss
Use less toilet paper per flush if you have an older low-flow toilet -- flush twice if needed rather than putting all the paper in at once.
Consider a dual-flush conversion for cisterns over 10 years old -- modern mechanisms give a stronger flush and use less water.
FAQs
Blocked Toilet Questions
Toilet Still Blocked?
London drain engineers, same-day clearance.
If DIY methods haven't cleared the blockage, a drain engineer can clear most toilet blockages on the same visit using professional rods and a high-pressure jetter -- no digging required.
No call-out fee on jobs over 2 hours · Same-day London · 24/7