Bathrooms 4 min read Updated 27 March 2026 Trade verified
Best Toilet Flush Valve UK — Ranked
Flush valves fail with limescale build-up on the seal. Here are the three UK trade favourites.
Need parts for this job?
Trade-priced dual flush valve in the Plumber.Parts catalog — next-day delivery.
Step-by-step method
Best universal — Wirquin Jollyflush
Fits 95% of UK dual-flush cisterns. Height adjustable, chrome buttons. £14.
Best Ideal Standard replacement — Siamp Optima 49
OEM for many mid-market UK toilets. Direct fit for Twyford, Vitra. £22.
Best drop-in retrofit — Fluidmaster K-053
Converts a leaking single-flush to dual-flush. Full kit £28.
Frequently asked questions
Why does my toilet keep running after flush?+
Flush valve seal warped or scaled. Replace the flapper/rubber (£4) or full valve (£14).
Dual flush vs single flush?+
Dual flush saves ~15L per person per day. Mandatory on new UK installs since 2001.