Toilets Explained

ABOVE: The Kapris WC from Jax Bathrooms (0121 753 6811)

NB: This is a close-coupled toilet with the cistern bolted directly onto the pan. Both inlet and overflow connections are made at the base of the cistern. Several designs of inlet and outlet valves have been developed in recent years.

1. Flush Push Button: This is a dual-flush toilet – so it can produce either a big (6L) or small flush (3- 4L). Two different buttons are housed within the CISTERN lid, attached to ‘actuator rods’, which engage the OUTLET VALVE on being pushed.

2. Inlet Valve: Fills the CISTERN with water after flushing, via an external supply pipe. You may be familiar with traditional valves using large float balls, but in newer toilets a plastic ‘Torbeck-type’ bottom-entry valve – or a ‘quiet ball valve’ – is common, which has a smaller float that may be clipped to the OUTLET VALVE. Water enters the CISTERN through the delivery tube at the bottom, which creates equal water pressure on both sides of the valve. This stops ‘water hammer’, making for a quicker and quieter flush. If the water in the tank runs constantly, then this valve is malfunctioning and may need replacing.

3. Outlet Valve: Controls the water entering the PAN. This is a plastic dual-flush outlet valve — when the larger FLUSH PUSH BUTTON, which has a longer actuator rod, is pushed, it lifts the valve sufficiently to engage in a latch, held by a small float. Water will flow from the cistern until the water level drops. When the smaller button is pressed, a shorter rod raises the valve only for a short period. A separate overflow is not needed because if the water level rises, it flows down through a central pipe within the valve from the CISTERN into the PAN.

4. Toilet Seat: A toilet seat is easily installed using two mounting bolts, fixed through washers into nuts. Soft-closing seats are an essential in big households.

5. Pan: The pan should be fixed to the floor using brass screws. When replacing a pan in an old house, check if it needs to have a floor or wall exit trap — or PAN OUTLET.

6. Pan Outlet: Connects to the SOIL PIPE via a FLEXIBLE CONNECTOR. Toilets generally have either an S-type or P-type trap, like this one.

7. Flexible Connector: A plastic push-fit connector which connects the PAN OUTLET to the SOIL PIPE. You might need an angled connector if installing in an old house, to match the height set for a previous fitting.

8. Soil Pipe: Leads sewage out of the house to the mains sewer. It must be connected to the PAN via a FLEXIBLE CONNECTOR — you’ll need to know the internal diameters of the soil pipe and PAN OUTLET to specify the size.

9. Foam Washer: Metal should avoid touching ceramic, otherwise there’s a risk of cracking — this washer prevents that.

10. Close-Coupling Plate: A thin metal plate fitted onto the underside of the OUTLET VALVE, which secures it to the CISTERN and connects it to the PAN. Bolts are inserted on either side of the plate.

11. Cistern: Houses the INLET VALVE and OUTLET VALVE, and holds a supply of water, ready for use when flushing. This is a close-coupled toilet so the cistern is seated on the back of the PAN. It can be connected to the wall with screws that are cushioned with tap washers or a cistern fixing kit, or alternatively by applying silicone sealant.

Find toilets, bathroom suites and sanitaryware in the Homebuilding Directory

Further reading:

• A Buyer's Guide to Toilets
• How to Fit a New Toilet
• A Guide to Heating and Plumbing