How do I fix a leaky cistern?

Everyone uses a compact toilet several times a day, thus flushing the water so often. After using the toilet for a long time, a malfunction can occur. A broken flush increases water loss, which leads to higher electricity bills. How can a flush be repaired?

Identify the fault

Before you start repairing the cistern, you should determine the location of the fault. This way you will know what parts need to be replaced and how time consuming the repair will be. The most common cause of failure is a faulty valve or broken seal.

Cistern design

A cistern available together with a toilet bowl usually consists of two valves:

• the first supplies water to the cistern,
• the second is for flushing the bowl.

The flush valve is closed by a bell which prevents water from flowing into the toilet all the time.

The most common cistern malfunctions

To repair a cistern, it is first necessary to find the cause of the failure. The most common causes of failure include:

• a leaking flush valve – the cistern cannot fully fill;
• the fill valve is leaking – the cistern keeps filling with water and then it pours out through the emergency overflow;
• the float has been incorrectly adjusted or has broken off the valve;
• faulty seal – water seeps from the cistern all the time, leaving a thin trickle of sediment inside the bowl.

Any of these faults needs to be repaired quickly as they can cause

• a higher water bill,
• having to replace the entire cistern or toilet bowl.

Simple cistern repairs you can do yourself if you can. If you don’t know how to fix a cistern, it’s better to leave the repair to a plumber or so-called handyman.

Flush repair – faulty fill valve

Repair a broken filling valve in a few steps:

1. Turn off the main water valve.
2. If there is water in the cistern, empty it.
3. Unscrew the drain button.
4. Remove the cistern cover.
5. Check the position of the float that is connected to the fill valve.
6. If the float is set incorrectly, the valve will not close and water will flow into the cistern all the time (you will hear water coming in).
7. Adjust the float setting.
8. If the float is correctly set, check the diaphragm in the valve.
9. Clean the diaphragm if it is dirty.

If the above treatments do not help, replace the valve with a new one.

Flush repair – broken flush valve

If the reason for your cistern’s failure is the valve responsible for the flush, then it’s usually just a problem of a broken flush valve gasket.

Replacing the gasket in a few steps:

1. Turn off the water valve.
2. Remove the cistern cover.
3. If there is water in the cistern, empty it.
4. Clean the gasket located in the cistern lock.

If this does not help, replace the gasket with a new one.

Cistern outlet gasket

If all the gaskets have been replaced and water is still pouring, then it’s a good idea to check the gasket located at the cistern outlet – it very often causes a failure, i.e. water oozing inside the toilet bowl.

Repair of a concealed cistern

Many people choose a concealed cistern, but what to do when the entire cistern is under tile? The most common cause of failure is the flush valve gasket. Very often, various contaminants accumulate under it, which cause this valve not to close. Then it is important to:

1. Replacing or cleaning the gasket under the valve.
2. Turn off the water.
3. Remove the plate and the plate that covers the rack.
4. Clean or replace the gasket.

If you are afraid to fix a leaky cistern yourself, leave it to a plumber or so-called handyman.