Plumbing emergencies
Toilet Overflowing? What to Do Right Now
Updated · Written by the SteadWell team
Stop the water first
The water in the bowl comes from the tank. Pressing the flapper — the rubber seal at the bottom of the tank — back onto its seat stops more water from entering the bowl. Then close the supply valve on the wall behind the toilet.
- Turn the oval valve handle clockwise until it stops
- If the valve is stuck, close the main shutoff for the house
- Put towels down; bowl water from a clog is usually clean, sewage backup is not
One toilet, or the whole house?
Check the tub and the lowest floor drain. If only the toilet is affected, it's a clog in the toilet or its short drain run. If water rises in the tub when the toilet is flushed, or several drains are slow, the blockage is further down in the main line, and more flushing will push sewage into the house.
Clearing a toilet clog
Use a flange plunger — the kind with a soft sleeve that seals into the drain opening — with steady, firm strokes. A closet auger reaches clogs a plunger can't. Avoid chemical drain cleaners in toilets; they rarely work on toilet clogs and make the water hazardous to anyone who has to clear it.
When to call a plumber
Call if the toilet clogs repeatedly, if water rises in other fixtures, if you see sewage, or if the toilet rocks or leaks at the base after the overflow. A toilet that clogs every week usually points to a drain line problem, and a base leak means the wax seal needs replacing.
This guide is general information, not a substitute for an on-site assessment. Read our editorial standards.