Overflowing or Blocked Toilet in London

A rising pan has one mercy: it usually stops just below the rim.

The job is knowing whether the blockage is in the pan, the branch or the shared run, because that decides whether it’s a plunger, an auger or the drain kit.

Overflowing toilet in London: do this now, while you wait

1. Don’t flush againThe tank holds another six litres. If the water is high, a second flush puts it on the floor.

2. Stop the refillLift the cistern lid and prop the float up, or close the isolation valve on the supply pipe (slotted screw, quarter turn).

3. Try one careful plungeA proper flange plunger, slow push, sharp pull. If two attempts don’t shift it, stop, enthusiastic plunging past that point damages the pan seal.

4. Check the other fixturesIf the shower or sink gurgles when the toilet fills, the blockage is downstream in the shared run, a different job, and useful to know before we arrive.

What causes an overflowing toilet in London

• The unflushables. Wipes, cotton wool, sanitary products, toys, the branch pipe’s greatest hits.
• Scale in the pan outlet. Hard-water scale narrows the trapway over years until a normal flush can’t clear it.
• Downstream blockage. The toilet is just the lowest point, the real blockage is in the run beneath the house.
• A failing macerator. On Saniflo-type installations, the pump not the pipe is usually the culprit, a specialism of ours.

Local conditions we work around

Above ground-floor level in a London conversion, an overflowing WC is an urgent problem for the flat below as much as for you. Houses split into flats commonly stack new bathrooms onto a waste stack sized for one household, so a blockage backs up to the lowest appliance on the stack rather than staying where it started. Isolating at the WC and stopping anyone else in the building running water matters more in the first ten minutes than anything we can do en route.