How to fix a leaking concealed cistern? Find out!

A leaking concealed cistern is a problem that is not only irritating but can also lead to more serious damage in the bathroom. Although it may seem that repairing such a unit is complicated, in reality most faults can be fixed on your own. Wondering how to do it? Below, we explain how to identify the causes of a leaking concealed cistern and how to carry out an effective repair. Do read on!

Concealed cistern – what is it?

A concealed cistern is a system that triggers the flushing of water into the WC pan. Such a toilet cistern is hidden within the wall, so it is not visible at first glance. Thanks to this solution, the bathroom looks more aesthetically pleasing and the space is better utilised.

This system consists of a flushing mechanism mounted inside the wall, accessed via a service panel, usually located behind the flush button. Although concealed cisterns are popular for their aesthetics and functionality, their repair may seem more complicated than that of traditional cisterns. Don’t worry about that in advance, though!

Leaking cistern: causes

A leaking cistern in a concealed installation can have several causes. The most common are:

• Dirt and deposits — limescale and other build-up can accumulate on parts of the cistern mechanism, hindering its proper operation.
• Incorrect settings — sometimes the problem may stem from improper adjustment of the cistern mechanism, causing it to work incorrectly.
• A damaged or sticking inlet valve — this can cause a continuous inflow of water into the cistern and an overflow.
• A damaged flush valve seal — the seal can wear out or crack, causing a leak and water seeping into the WC pan.

How to fix a leaking concealed cistern?

This problem does not always require calling in a specialist. You can tackle the repair yourself by following the step-by-step guide below.

Step 1: Turn off the water supply

Before you start any work, turn off the water supply to the cistern. The valve is usually located near the toilet. This will protect you from flooding the bathroom.

Step 2: Open the service panel

Using an appropriate tool, such as a screwdriver, open the service panel to access the cistern mechanism. Do this gently to avoid damaging any components.

Step 3: Check the inlet valve

Inspect the condition of the inlet valve. If it is damaged or shows visible signs of wear, replace it with a new one. Inlet valves are available at most plumbers’ merchants — remember to choose a model compatible with your existing fittings.

Step 4: Check the flush valve seal

Examine the flush valve seal. If it is worn or cracked, replace it with a new one. Make sure the new seal is properly matched to your cistern model.

Step 5: Remove dirt and deposits

Remove any dirt and deposits from the components of the cistern mechanism. You can use special cleaning agents or a soft cloth and vinegar.

Step 6: Check the mechanism settings

Make sure the cistern mechanism is correctly adjusted. Sometimes a slight adjustment is all it takes for the cistern to work properly.

Step 7: Testing

Once you’ve completed the steps above, turn the water supply back on and test the cistern’s operation. Make sure the leak has been eliminated.

Leaking cistern: get rid of the problem and enjoy peace of mind

A leaking concealed cistern is a problem you can solve yourself if you know the basic causes and repair methods. It is worth regularly checking the condition of the cistern and its components to avoid more serious faults and costly repairs. Remember that a well-functioning cistern means not only comfort but also savings in water and money. If, however, the repair is beyond your capabilities, contact a professional plumber who will resolve the issue quickly and effectively.