How to Fix a Leaking Toilet or Cistern

A leaking toilet is one of those annoying plumbing problems that can happen from time to time. However, a leaking toilet can often be fixed by yourself without needing to call a plumber.

Before delving into how to fix a toilet, it is important to briefly explain how toilets work; this will help both with diagnosing the issue as well as resolving what the problem is. If you are not familiar with a lot of plumbing issues or problems, especially those about toilets, then it would be a good idea to lift off the lid and flush it a few times to see how the process works.

Each toilet can vary to some degree, and knowing how this works would be a good idea. Generally, when you flush the toilet the action will start a reaction, wherein a chain link or arm will lift what is called a “flapper”. This lets the water refresh into the toilet bowl.

There is a float that is connected to the valve that falls and signals when to fill the toilet with water. When this float reaches the bottom, it signals to the valve to close the flapper and begin to fill the tank with water again. Additionally, the toilet will also contain a tube for overflow that takes water out into the basin if the water level gets too high.

Problems That you May Run Into

The Flapper

Occasionally, the flapper can get stuck which will cause a constant flow of trickling water into the toilet bowl. Usually, the reason for this is the flushing mechanism inside hitting something, or the flapper itself getting stuck. For instance, the flapper may not be lined up correctly, or maybe wedged in such a way that prevents it from closing.

The best way to fix this problem is to re-situate it so that it settles back into place after being lifted from flushing the toilet. Sometimes the rubber seal may need to be replaced, or older flappers can accrue sediment; most of the time, they can be simply cleaned by using a cloth to fix the issue.

The Water Valve

Ensure that the level of water in the toilet is at the water level line. If you notice that the water level seems to be on the low side, this can be an indicator that the float will need to be adjusted. For the toilet to fill the way it was designed, you will want to double-check that the water valve is turned on completely.

The Float Valve

After completing the above-mentioned step, you will now want to double-check that the float valve is shutting off correctly. If when you lift on the float and the running of water stops, you will now need to raise or lower the level that the float is at, or maybe the washers in the inlet valve are due for replacement.

Additionally, it is worth mentioning that overflow problems can also be caused by excessive pressure. By adjusting the valve, you might mean moving the float down somewhat, just making sure that it is not touching or obstructed by anything else. If the issue that you are experiencing is leaking outside of the toilet bowl, this signifies that there is a problem outside of the cistern.

This should be taken care of as soon as you are able, as damage to your floors can result in a lot of money spent to repair.

The Drainage System

The system used for drainage of your unit may be the reason for the leak if water is coming from between the toilet and floor. While this is not an easy fix and will require removing the toilet, it would be wise that for a problem of this magnitude that you use the services of a professional plumber.

Broken Flushpipe Seal

If the leak seems to be centered more high up, this is probably an issue with the seal between the tank and bowl; this may need to be replaced. To replace this seal, you will want to raise and separate the bowl from the tank. This may be easier to accomplish with the help and guidance of a professional plumber.


Hopefully, this guide helped you fix your toilet plumbing problem. Most plumbing processes, such as fixing a toilet cistern are not difficult and can be done by yourself. However, some plumbing activities require specialised tools that you may need to purchase.

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