How to Replace a Toilet Fill Valve (UK)
Fit a bottom-entry or side-entry fill valve on UK cisterns. Fluidmaster, Torbeck, Siamp part numbers.
FluidmasterTorbeckSiampGeberit
Bottom vs side entry
Check where the water pipe enters the cistern. Bottom-entry = valve mounts through the base. Side-entry = valve mounts through the side wall.
Recommended parts
- Fluidmaster 400UK — universal bottom-entry, quietest on the market.
- Torbeck Ecofil TS3S — side entry, ½".
- Siamp 95-3220 — Geberit compatible.
- Geberit Impuls 380 — for UP frames.
Fit
Isolate at service valve. Flush. Sponge base. Undo backnut (25 mm). Fit new valve with fresh fibre washer. Set fill level to 25 mm below overflow.
Frequently asked questions
- Why does my new fill valve hammer?
- High mains pressure. Fit a Fluidmaster Pro 400H or add a service valve with flow restriction.
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