Toilet flush buying guide

In order to choose the right flush system, you will have to look at your cistern and take note of some measurements. Rest assured this process is fairly straightforward and shouldn't take more than five minutes!

• Measure the hole in the cistern lid (b) where the flush button will be installed (the diameter should range from 16 to 50 mm).

Toilet flush parts and assembly

The toilet flush is simply the system that allows wastewater to be flushed from the toilet bowl and be replaced by clean water.

Its basic operation centres around a certain amount of water being released from the cistern in one go. This volume of water creates a flow that carries away the waste and toilet paper.

The toilet cistern is connected to a water supply pipe at one end and the toilet bowl at the other. It also contains the toilet's key component: the flush mechanism, which is used to regulate the inflow and outflow of water in the system.

Nowadays, flush systems are installed directly above the toilet bowl – gone are the days when flushing meant ceramic cisterns would have to be installed two metres above the bowl and operated by a pull chain!

The control used to operate the flush system is found at the top of the cistern. There are several different control types: lever handles, pull handles, single push buttons and dual push buttons.

Flush control: pull handles or push buttons

• Pull handles: These controls require you to pull up a metal rod to open the flush system and release water from the cistern into the toilet bowl. This system is generally considered outdated as it does not allow you to control the amount of water released with each flush.

Connecting the push button to the flush mechanism

The dual push button sends information to the rest of the mechanism through a control system. There are several different possibilities:

• Cable: the push button (or pull handle) is connected to the flush mechanism by means of a cable. The advantage of this system is that you can access the cistern without having to remove the button. This mechanism is also compatible with remote flushes (which can be installed to the side of the toilet lid). 

• Mechanical control: the push control or pull handle is connected directly to the flush mechanism. The advantage of this system is that it tends to be more durable. It also allows you to easily adjust the amount of water released (when using push buttons). The biggest drawback of some pull models is that you have to remove all or part of the button to lift the cistern lid and their use is usually restricted to the hole found in the middle of the lid.

You can also opt for a combination of cable and mechanical controls, allowing you to take advantage of both system types.

Toilet fill valves 

The cistern is linked to the water network of your home by a special valve.

This fill valve is connected either below or on the side of the cistern. It is also attached to a float and a flush valve designed to stop the cistern from filling once it contains a certain volume of water.

Side-entry fill valve  

This type of fill valve is connected to the side of the cistern and tends to be quite noisy as the water level increases on the surface. Side-entry fill valves feature a screw that comes in a standard size (12x17) and these are generally made of chrome-plated brass.

Bottom-entry fill valve

Bottom-entry fill valves send water into the cistern from below, meaning they make little or no noise when refilling. The fill valve is connected to a flow control device equipped with a float. The float shuts off the valve when the water in the cistern reaches a maximum level.

Toilet floats

Toilet fill systems are generally supplied as a fill valve and float in one single part. There are two main types of float:

• Float ball valve: the float shuts off the valve via a lever to stop the flow of water.

• Float cup valve: the float rises along an axis or track shutting off the valve to stop the flow of water.

Making sure your flush mechanism is in perfect working condition will end up saving you money in the long term. Do not ignore any leaks or faulty parts as this will end up increasing your water bill. Most leaks are caused by seals that are in poor condition or covered in limescale. Take care to clean your flush mechanism regularly  - especially if you live in an area with hard water. Limescale can build up in the joints of the mechanism and can affect the seal between the cistern and the toilet bowl.

Flush systems are very easy to install; this should be a very straightforward task as long as you follow the assembly instructions and choose the right model for your cistern. While many flush mechanisms come in standard sizes and can be adapted to fit any type of cistern, you should still measure your tank before buying a new flush.

Lastly, please ensure you cut off your water supply before attempting to remove your toilet flush!