What to do if…
a toilet keeps refilling or overflowing and you cannot stop it

What to do now

1. Make a safer pause (10–30 seconds): move towels/bathmats out of the way so you don’t slip. If water is spreading toward sockets, appliances, or light fittings, keep people/pets out of the wet area.
2. Try the toilet’s isolation valve (fastest): look for a small valve on the pipe feeding the toilet (often behind/next to the pan or cistern). Turn it clockwise until it stops.
   • If it’s a slot-head isolation valve, use a flat screwdriver and turn clockwise to the stop. (The slot often ends up across the pipe, but the key check is whether the refilling stops.)
3. If that doesn’t work, turn off the property’s mains water: use your inside stop valve/stopcock (often under the kitchen sink, in a utility cupboard, or near where the water pipe enters the home). Turn clockwise until it stops.
4. Relieve pressure (only once the water supply is off): if the level is still high, flush once (or hold the flush briefly) to lower the level and reduce spill risk.
5. Limit damage immediately: use towels to dam water away from doorways and electrics; place a bowl/container to catch drips if water is tracking down the outside of the cistern. If safe to do so, open a window for ventilation.
6. Contact the right “repair route” now (don’t wait):
   • If you rent: contact your landlord/letting agent’s emergency repairs route and clearly say: “toilet is overflowing / I had to turn the water off.”
   • If you own: call an emergency plumber.
   • If water has affected a shared area (e.g., flats), inform the building manager/freeholder if you have one.
7. If you had to turn off the mains: let others in the property know (so nobody turns taps on and walks away), and avoid running appliances that rely on the water supply until repairs are underway.