Full Siphon Assembly
Also known as: toilet siphon, flush siphon, piston
The complete siphon unit used in older UK cisterns. The entire mechanism creates the flush by using a siphonic action rather than a simple flap valve.
Inside the cistern, attached to the flush handle lever and bolted to the base of the cistern.
Plastic or metal tube with a bell-shaped bottom and a lever arm. Requires draining the cistern to replace.
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Always turn off the water supply before replacing any part. If in doubt, consult a qualified plumber. Gas components must only be worked on by a Gas Safe registered engineer. Unvented (pressurised) hot water systems must be worked on by a G3-qualified engineer. Prices shown are indicative — check retailers for current pricing.