Thomas Dudley Elite Panel Bottom Supply, Bottom Outlet 6 9 Litre Cistern, Toilet Flush Valve, WC Dual Flush Syphon, Replacement Flushing Valve, White

Toilet spares keep a WC cistern filling, flushing and shutting off as it should. This category covers fill valves (also called float valves or ball valves), flush valves and siphons, push buttons and levers, flush pipes, cistern service packs, tap connectors with isolating valves, and support frames for wall-hung pans, basins and bidets.

Fill valves

The fill valve lets water into the cistern and closes when it reaches the set level. Start by checking where the supply enters: bottom entry valves rise from the base of the cistern, while side entry valves fit through the side wall. Then match the shank size, usually 1/2 inch with 3/8 inch on some cisterns, and choose a plastic or brass shank. Many bottom entry valves adjust in height to suit different cisterns. A servicing valve on the supply pipe next to the cistern lets you isolate it for repairs.

Flush valves, siphons and buttons

• Flush valves: lift to release water and are worked by a lever, a cable from a push button, or air from a pneumatic button, which is common on concealed cisterns.
• Siphons: the traditional alternative, worked by a lever or a push button.
• Buttons and levers: match the operating type and the size of the hole in the lid or cistern front.

In England and Wales, under the Water Supply (Water Fittings) Regulations 1999, a WC flush must not exceed 6 litres, the smaller flush on a dual flush must be no more than two-thirds of the full flush, and the cistern needs a warning pipe or an equally effective overflow arrangement.

Finding the right part

Note any make or model marked inside the cistern, measure the old part and compare it before buying. For complete units, see toilets; for isolating and servicing valves, see valves.