How to unblock a toilet that's badly blocked

Before you start

• Stop flushing. Each flush adds water to a pipe that can't drain.
• Turn the cistern tap off at the wall.
• Put old towels around the base and wear gloves.
• If the bowl is close to the rim, bail some water into a bucket first.

Method 1: a flange plunger

A toilet plunger has a soft flap (the flange) that seals into the outlet. Push down gently to get the air out, then plunge firmly 15 to 20 times while keeping the seal. Do a few rounds before giving up. A flat sink plunger won't seal properly.

Method 2: hot water and dishwashing liquid

Squirt dishwashing liquid into the bowl, add a bucket of hot (not boiling) water, wait 20 minutes, then plunge again. Boiling water can crack the porcelain.

Method 3: a toilet auger

A toilet auger has a protected bend so it won't scratch the bowl. Feed it into the outlet, crank the handle to break up or hook the blockage, then pull it back. Turn the cistern tap back on and test with one flush, ready to turn it off again.

Signs it's the sewer, not the toilet

• Water rises in the shower or floor waste when you flush.
• Other drains are slow or gurgle.
• The overflow gully outside is wet or overflowing.
• The toilet blocks again within days.

What not to do

• Don't keep flushing to test it.
• Don't pour chemical drain cleaner into a toilet. It rarely works and makes the job unsafe for the plumber.
• Don't use a wire coat hanger. It scratches the porcelain and rarely reaches the blockage.

What a plumber charges

In Sydney, a blocked toilet typically costs $180–$350 to clear in business hours, and more after hours. Block Drains clears a blocked toilet for $249 fixed at any hour, with no call-out fee. If the blockage is in the sewer line rather than the toilet, it's a sewer job, which typically costs $300–$800.

Questions

Will a blocked toilet unblock itself?

Sometimes, if it's only toilet paper and you leave it a few hours to soften. Wipes, sanitary items and objects won't break down.

Can I flush 'flushable' wipes?

No. Wipes don't break down like toilet paper and are one of the most common causes of blocked toilets and sewer lines.

Who pays for a blocked toilet in a rental?

In NSW a blocked toilet is an urgent repair, and the landlord generally pays unless the tenant caused it, for example by flushing wipes.

What if my home is on a septic tank?

The plunger and auger methods are the same, but never use chemical drain cleaners, which kill the bacteria the tank relies on. If several fixtures drain slowly at once, the tank may need pumping out rather than the toilet unblocking.