If the bowl is filling up
Don't flush again
Another flush only adds water to a pan that can't empty. Give the level time to drop.
Stop the cistern refilling
Many toilets have a small tap or valve on the water pipe to the cistern. Turning it off stops more water arriving.
Check the rest of the house
Run a little water in the shower, or look at the gully trap outside. If either is backing up, the main drain is the problem, not the toilet on its own.
Protect the floor
Put old towels around the base of the pan, and keep children and pets out of the room until it's sorted.
Signs it's more than the toilet
- The shower or bath bubbles, or water rises in it, when you flush.
- The gully trap outside is wet or overflowing.
- Every toilet in the house is slow, not just one.
- It blocks again within days of being cleared.
- There's a sewage smell around the house or yard.
What usually blocks a toilet
Inside the pan, the usual culprits are wet wipes, sanitary products, cotton buds and too much paper in one go. Children's toys and dropped items lodge in the bend too. Tauranga City Council says most wastewater blockages happen when things like wet wipes, fats and cooking oils go down toilets and sinks.
Further along, tree roots in a joint, a cracked or sagging pipe or a blocked section of the drain can stop a toilet emptying even when nothing is wrong with the pan itself. That's when the problem shows up in other fittings too.
What a plumber will do
A plumber will first work out whether the blockage is in the pan or beyond it, by running other fittings and checking the gully trap.
For a pan blockage, they'll usually use a toilet auger, a short flexible cable designed to get round the bend without scratching the bowl. If that won't shift it, the pan may need to come off the floor so the outlet can be cleared from behind. Removing and refitting the pan is sanitary plumbing, restricted work under the Plumbers, Gasfitters, and Drainlayers Act 2006.
When the drain itself is blocked, a plumber or drainlayer goes in from the gully trap or an inspection opening with a drain machine or a hydro jetter. If it keeps happening, a camera inspection shows why. Our blocked drains page covers that side in more depth.
What changes the job
- Pan or drain: a blockage in the pan is usually the shorter job.
- What's stuck: paper breaks down, but a toy or a wad of wipes may need fishing out.
- Access to the drain: a clear inspection opening helps, and one under decking or paving has to be found.
- The pipe's condition: roots or a broken section mean repairs rather than a clear.
- Whose pipe: a blockage past your boundary goes through your council's or provider's process.
Your drain or the council's?
Who looks after the pipe beyond your toilet depends on your council or water provider, and the rules aren't the same everywhere. Three we've confirmed:
Whanganui: if a sewer pipe or toilet is blocked, the owner calls a plumber to investigate. The plumber finds where the blockage is, and if it turns out to be in the council's network, the council is invoiced.
Napier: for a toilet, shower or sink that won't drain, the council says you may need a plumber or drainlayer to investigate, and to contact the council if the problem is found at the boundary. It won't pay for camera inspections or jet cleaning to find the cause.
Palmerston North: the council doesn't unblock pipes on private property, and says that if wet wipes block yours, you'll be covering the plumber's cost.
Other places run their own rules. Check who fixes a blocked drain, or your city page such as Whanganui, Napier or Palmerston North.
What you can try, and what to leave
You can
- Use a flange plunger, made for toilets, with firm steady pushes once the water level has dropped.
- Clearing a blocked drain is on PGDB's homeowner list, as long as the inspection pipe and vent pipe are left alone.
- Sort a cistern that keeps running: PGDB's list also lets homeowners repair or replace ball cocks.
- Tell the tradie if you've already tried a chemical cleaner.
Leave to an authorised tradie
- Taking the pan off or putting it back: PGDB says homeowners can't fix or unfix a fixture or its pipes.
- Clearing the drain with machines or jetters.
- Anything touching the inspection pipe, vent pipe or gully trap.
- Repairs to a cracked or root-damaged drain.
Licences
Check the person, not the business. PGDB's Ask for Licensed campaign says to search the tradie's first and last name on the register, because it doesn't recognise business names, and to look for a tick or green showing a current licence. Our PGDB licence guide walks through it.
Like-for-like repairs to sanitary plumbing or drainage, using comparable products, don't need a building consent when an authorised person does them. The work still has to meet the Building Code.
Red flags
- Can't show a current PGDB licence, on a card or in the app, when you ask.
- Wants to sell you a new toilet before finding out whether the drain is blocked.
- Says the blockage is on the council's side but can't show you where or how they know.
- Recommends digging up the drain with no camera footage to back it up.
What we would do
Give the plunger a fair go if only the toilet is slow and nothing else is backing up. If the shower bubbles when you flush, or the gully trap outside is wet, put the plunger down: the drain is blocked, and pushing harder won't fix that. Get a plumber or drainlayer to clear the line, tell you what caused it, and note whether it was on your side of the boundary.