Toilet won't flush, or flushes weakly

Likely cause

A clogged trap/drain line, or a worn flapper/fill valve not delivering enough water to clear the bowl.

What to try first

• Try a plunger with firm, steady strokes for 30-60 seconds before calling anyone.
• Lift the tank lid — check if the chain connecting the flush handle to the flapper has come loose or disconnected.
• If water is rising toward the rim, turn the shut-off valve behind the toilet clockwise to stop it before it overflows.