First, stop flushing
Every extra flush adds water to a pipe that cannot take it. If the pan is near the rim, leave it. The level will usually drop over an hour or two if the blockage is partial, and that alone tells you the pipe is restricted rather than fully blocked.
Check whether it is only the toilet
Run the bath, the basin and the kitchen sink. If they all drain normally and only the toilet is affected, the problem is almost certainly in the pan trap or the short branch behind it. If sinks gurgle, the shower backs up or water rises in the bath when you flush, the blockage is in the shared soil pipe or the underground drain, and it needs clearing properly.
Safe things you can do yourself
- Use a proper toilet plunger with a flange, not a flat sink plunger. Slow, firm pushes, not fast ones.
- Pour a bucket of warm, not boiling, water in from waist height. Boiling water can crack ceramic.
- A closet auger designed for toilets can clear paper and small items in the trap.
- Look in the pan with a torch for an obvious object. Toys, air fresheners and cleaning blocks are common.
What not to do
- Do not use caustic drain cleaner in a toilet. It sits in standing water, does not clear the blockage and makes the job hazardous for whoever works on it next.
- Do not force rods without knowing the pipe layout. You can push a blockage into a bend or damage older pipework.
- Do not keep flushing to test it. That is how a toilet ends up over the floor.
Check the outside chamber
Lift the nearest inspection chamber cover if you can do so safely. If it is empty and dry, the blockage is between the toilet and that chamber, so it is inside your property. If the chamber is full of water and sewage, the blockage is downstream of it, further along the run.
In a flat, a tenement or any shared building, a full chamber often means the shared drain serving several properties is blocked, and clearing one flat's waste pipe will not solve it.
When to call
Call straight away if sewage is coming up into the bath or shower, if the chamber outside is full, if more than one appliance is affected, or if the property has only one toilet. These are same day problems, and we answer the phone around the clock.
Questions we get asked
Why does my toilet gurgle when the sink drains?
Gurgling is air being pulled through the trap because the pipe below is partly blocked or the soil vent is restricted. It is an early warning that the run is closing up.
The toilet drains slowly but does not overflow, is that urgent?
It is not an emergency, but it will get worse. A slow pan is a partly restricted pipe, and the restriction rarely clears itself.
Who pays if the blockage is in a shared drain?
In a shared building the cost is normally split between the properties the drain serves, and a factor may organise it. Our report and camera footage show where the blockage was so the split can be agreed fairly.