How to Install a Water Cistern in 4 Steps

What You'll Need
Flexible connector pipe and related fasteners
Rubber gloves
Spirit level

Whether you are going through a complete refurbishment or just seeking to change a small aspect of your bathroom, knowing how to install a water cistern can be a useful skill. Though it may seem like a challenging task, you will find it a relatively simple job if you follow a few easy steps.

Step 1 – Drain Out Water

Start the process of removing the water cistern by turning off the water supply to the toilet. Lift the lid from the cistern and set it aside on a flat surface; if you have the style of cistern where the flush lever is built into the top of the cistern, this will first need to be removed by unscrewing it. Drain the remaining water by flushing until the toilet bowl and cistern are both empty. Use some rags to soak up the last traces of water in the cistern.   

Step 2 – Remove Existing Cistern

Check inside the existing water cistern to determine whether it is fastened to the wall with screws. If it is, start by removing these screws and retain any washers that have been used with them. Move to the base of the cistern to undo the connection of the cold water pipe. The pipe is likely to be flexible so you will need to brace it at one side of the connector with a pair of pliers while you loosen the nut with a wrench to remove it effectively. Check the internal base of the cistern which should have fastenings that lead to the corresponding external area of the cistern. Depending on the style of cistern, these may be butterfly nuts which can be loosened by hand but you may need to use whichever tool is relevant to the fittings. The tank should then be able to be lifted out of place.

Step 3 – Position New Water Cistern

Carefully lift the new cistern into place with the inlet pipe in line with the pre-drilled hole in the tank. All the relevant fasteners should be included with the cistern to enable it to be secured. If there are no pre-drilled holes in the cistern to secure it to the wall, you can attach a block of wood to the wall behind the cistern and cover it with tiles and sealant. Position the lid on the water cistern and check with a spirit level to ensure it is sitting straight. Once this has been established, remove the lid and secure the cistern in place with the fasteners at the base.   

Step 4 – Assemble Mechanism

Reattach the cold water pipe by reversing the method you used to remove it. Brace one end with a pair of pliers and tighten the nut with a wrench. Manufacturer’s instructions should be included with the cistern which will confirm how to assemble the flush mechanism inside the cistern. Once this has been fitted, turn the water supply back on and watch to see if the cistern refills as it should. You must also observe to make sure that there are no leaks. Flush the toilet to test that the water drains correctly to finish the task.