Wall-hung toilets and concealed cistern frames explained

A wall-hung toilet has no foot on the floor. The pan sticks out from the wall, and the cistern is hidden inside the wall or behind a panel. All you see is the pan and a flush plate on the wall above it.

They make a small bathroom look bigger and the floor is easy to clean. The trade-off is that most of the toilet is hidden, so planning matters before the walls are closed up, and repairs go through the flush plate opening. This guide explains how the system works and who usually fits it.

How it works

A wall-hung toilet has three main parts:

1. The frame. A steel frame fixed to the floor and to the wall or studs behind. It carries the weight of the pan and the person using it, and holds everything else in position.
2. The concealed cistern. A plastic cistern built into the frame. It has a fill valve and a flush valve like any cistern, but they are reached from the front through the flush plate opening.
3. The pan. Bolted to the frame through the finished wall, with short connections to the flush outlet and the soil pipe.

The frame is boxed in with boards and tiled, or hidden behind fitted furniture. The flush plate (buttons) covers the opening into the cistern.

Concealed frames from makers such as Geberit, Grohe, Wirquin, Siamp and others work in broadly the same way, but the parts are specific to each maker. When you buy, note the brand and model of the frame and cistern. You will need them to find parts later.

Compared with a close-coupled toilet

A close-coupled toilet is the most common UK type: a floor-standing pan with the cistern bolted directly on top of the back of it. Everything is visible and reachable. Our guide to close-coupled, low-level and other toilet types compares the main styles.

	Close-coupled	Wall-hung
Cistern	On the pan, visible	Inside the wall
Weight carried by	The floor	The frame
Access to valves	Lift the lid	Through the flush plate opening
Changing it later	Usually a like-for-like swap	Frame stays; pans and plates must suit it
Planning needed	Low	High, before walls are boarded

A back-to-wall toilet is a halfway house: a floor-standing pan pushed against a unit or false wall, with the cistern hidden behind. It shares the hidden-cistern access issue but not the frame.

First fix: why the frame is a plumber's job

The frame goes in at first fix, before boarding and tiling, alongside the other hidden pipework. It is usually fitted by a plumber because it involves:

• fixing the frame securely to a floor and wall that can take the load;
• setting the height of the pan, which is fixed once the wall is built;
• running the cold supply to the concealed cistern, with an isolation valve that can be reached later, often through the flush plate opening;
• connecting the frame's soil outlet to the soil stack with the right fall;
• testing the cistern and connections before they are covered.

Get it wrong and the fix means taking down a tiled wall. Our bathroom refit order guide explains first fix and second fix, and why the toilet should be chosen before the plumber's first visit.

Frames come in different heights and depths. A lower frame fits under a window or in a boxing; a full-height one fixes to the wall. The pan must be one the frame maker says is compatible, and the bolt centres and connections must line up.

The flush plate and access

On most concealed cisterns, the flush plate unclips or lifts off to reveal an opening into the cistern. Through it you can usually reach:

• the isolation valve for the cistern, if the installer fitted it there;
• the fill valve, which may lift out for cleaning or replacement;
• the flush valve and its seal.

How the parts come out varies by maker. Some need the valve removed in a set order; some need a specific tool. Use the cistern maker's instructions for that exact model.

If the cistern runs on into the pan, the cause is usually the same as on any toilet: a worn flush valve seal or a fill valve that does not shut off. Our guides to a running toilet and toilet fill and flush valves explain the parts. The difference is that you reach them through the plate opening, not from above.

If the plate opening does not give enough access, or the cistern itself is leaking inside the wall, call a plumber.

The pan connection

The pan connects to the frame's soil outlet through short spigots and seals, and to the cistern through a flush pipe connector. A leak at either shows up as water on the floor under the pan or a damp patch on the wall below. Our WC pan connector guide explains soil connections and how to tell clean water from waste. On a wall-hung toilet, the connectors are specific to the frame, so check the maker's parts.

Example frame at Wickes

We haven't tested this. It is an example, with what the retailer's page says.

We haven't tested this. Figures are as the maker states them (checked 13 November 2026).

Are wall-hung toilets harder to repair?

Not always harder, but different. The fill and flush valves are reached through the flush plate opening instead of under a lid. Parts are specific to the frame maker, so keep a note of the brand and model.

Can I fit a wall-hung toilet frame myself?

It is usually a first-fix job for a plumber. The frame has to be fixed to take the load, set at the right height, connected to the soil stack with the right fall and tested before the wall is boarded. Mistakes mean opening up a tiled wall.

Can I change a close-coupled toilet for a wall-hung one?

Yes, but it is a bigger job than a straight swap. It needs a frame, a boxed-in or rebuilt wall, a new supply and soil connection, and redecoration. It is best done as part of a bathroom refit.