How to Unblock Toilet

A blocked toilet is stressful, but in most cases you can clear it yourself in under 15 minutes with the right tool. The key is to act methodically, escalate through the methods below rather than reaching straight for chemicals, which can damage older pipework and rarely shift solid blockages anyway.

This guide walks through every approach from plunger to plumber, with realistic UK costs for 2026.

Why Toilets Block

Most blockages are in the toilet trap, the curved section built into the porcelain base, or within the first metre of waste pipe. Common causes:

• Excessive toilet paper, especially thick or quilted types
• Wet wipes, including many labelled “flushable”: most do not break down quickly in the sewer, and only wipes carrying the water industry’s Fine to Flush symbol have passed its disintegration tests¹
• Children’s toys, hygiene products, or cotton wool
• Partial build-up over time (limescale, tissue residue) narrowing the pipe
• Modern low-flush WCs, whose single flush is capped at 6 litres by the Water Supply (Water Fittings) Regulations 1999, struggling to carry waste along long or shallow-fall soil pipe and drain runs in older houses²

If multiple fixtures are draining slowly or backing up at the same time, the blockage is further downstream, likely in the soil stack or main drain, and requires a plumber or drainage contractor.

Method 1: Plunger

A toilet plunger (also called a flange plunger) has a rubber flap that extends into the drain opening, forming a proper seal. A flat cup plunger designed for sinks will not generate enough force, get the right tool.

Steps:

1. Put on rubber gloves and lay old towels around the base.
2. Check the water level in the bowl. If it’s very high, use a bucket to remove some to avoid overflow.
3. Insert the plunger so the rubber flange seats into the drain opening.
4. Push down firmly to expel air, then pull up sharply without breaking the seal. Repeat 10–15 times in a steady rhythm.
5. Pull the plunger away quickly on the final stroke to release suction.
6. Flush cautiously, hold the handle but be ready to stop if it backs up.

Most simple blockages clear in 2–5 minutes of plunging. If not, try again with more vigour before moving on.

Cost: £10–£25 for a quality flange plunger.

Method 2: Hot Water and Washing-Up Liquid

For a blockage caused by a build-up of material (rather than a solid object), this can help soften it before plunging again.

Pour a generous squirt of washing-up liquid into the bowl, followed by a bucket of hot (not boiling, boiling water can crack older ceramic) water from about waist height. The pressure and heat help break down the blockage. Wait 5–10 minutes, then plunge again.

Cost: effectively free.

Method 3: Toilet Auger (Drain Snake)

A toilet auger, also called a closet auger, is a coiled cable with a hand crank and a rubber-coated elbow to protect the ceramic. A typical hand auger has a cable around 1 m long, enough to reach past the trap.³

Steps:

1. Insert the rubber elbow into the drain opening.
2. Feed the cable in slowly while cranking the handle clockwise.
3. When you feel resistance, crank gently to hook or break up the blockage.
4. Retract carefully, if you’ve hooked a solid object, it will come out with the snake.
5. Flush and check.

Important: Do not use a standard drain snake without the rubber protection, the metal cable will scratch and crack the ceramic glaze inside the trap.

Method 4: Drain Cleaning Products

Chemical drain cleaners can help with grease or paper build-ups but will not shift solid objects. Caustic soda (sodium hydroxide) is effective but must be handled with care:

• Always wear chemical-resistant gloves and eye protection.
• Add the powder to cold water, never reverse this, in a plastic bucket.
• Pour carefully into the drain and leave for the time stated (typically 30–60 minutes).
• Flush with cold water.

Avoid: using chemicals after multiple plunging attempts have splashed contaminated water around, you’ll be at risk of chemical splash.

Enzyme-based products (e.g., Bio-Clean style treatments) work more slowly but are safer and better for older lead or clay pipework.

Method 5: Call a Plumber or Drainage Contractor

If methods 1–3 haven’t worked within 30 minutes, the blockage may be:

• A solid foreign object lodged in the trap
• A blockage in the soil stack or underground drain
• A structural defect (collapsed pipe, root ingress)

Get at least two quotes for anything beyond a straightforward callout. WaterSafe (www.watersafe.org.uk) lists plumbers who belong to water industry approved-plumber schemes, a useful starting point for finding qualified tradespeople.⁴

When It’s the Landlord’s Problem

If you’re renting, report a blocked toilet to your landlord immediately. Under section 11 of the Landlord and Tenant Act 1985, landlords on most tenancies of under seven years must keep the drains in repair and keep toilets and other sanitary installations in repair and proper working order.⁵ The landlord is not liable for problems caused by a tenant failing to use the property in a tenant-like manner, so do not pay for drain clearance yourself unless it’s clearly caused by your own misuse, and even then, get the landlord’s approval first.⁵

Preventing Future Blockages

• Only flush human waste and toilet tissue, nothing else.
• Avoid extra-thick “premium” toilet paper in older properties with long or shallow drain runs.
• Pour a kettle of hot water (not boiling) down the toilet once a month if you have a slow flusher.
• If an older property blocks repeatedly, have the drains checked with a CCTV survey before replacing anything: a sagging, cracked or root-damaged pipe is a more likely cause than the pipe’s size.

Most blocked toilets are a 10-minute job with a plunger. Keep one under the sink and the problem rarely escalates.