How to change a toilet flush

How to Change a Toilet Flush

There’s nothing worse than finding your toilet not flushing, particularly if it’s the only toilet in your house.

A toilet that doesn’t flush is a common plumbing problem that happens to most toilets at some point. Luckily, there are simple solutions you can implement yourself to get the toilet working again. This means fixing or replacing your toilet flush - but how do you do it?

Plumbworld is here to explain the process of removing and fitting a new toilet flush. We’ll also discuss the three types of toilet flush available to you when buying and how they differ from each other.

Read on to find out how to not only fix but change a toilet flush…

Why won’t my toilet flush?

why won't my toilet flush?

Your toilet may not flush properly or even at all for a number of reasons. If water comes up the bowl and doesn’t drain properly once you flush, you have a blockage. However, if the water in the toilet bowl is at its usual level, but water doesn’t flow down from the cistern, then the problem lies in the cistern flush mechanism. You may have one of the following issues:

  • Low water level in the cistern/tank
  • Faulty flushing mechanism
  • Broken toilet handle
  • Flush link not properly connected

What are the types of toilet flush controls?

what are the types of toilet flush?

When it comes to toilet flush controls, there are typically, three types. These include the traditional lever/handle up to buttons. We won’t cover automated or sensor controls but this is the technology coming into your bathroom soon. The three main control types are:

  • Traditional lever: This is the classic toilet flushing control that doesn’t offer any control over the volume you can flush.
  • Single push-down button: This control type is more modern than the lever type but still doesn’t offer any control over flushing volume.
  • Double push-down button: This type saves water by offering a choice between a part flush or a full flush. The smaller button in this control releases about half the volume flushed by the larger control button.

How to change a toilet flush handle

how to change a toilet flush handle

The process we will guide you through is changing a toilet flush handle. While many modern toilets will feature button controls, the handle is still popular and is likely the most common in UK homes.

Removing the Old Handle


First, you need to turn off the water supply to your toilet and remove the cistern lid. The valve controls the water supply and is attached to the pipe or wall behind your toilet. Turn the valve clockwise to close off the water supply. Put the cistern lid on a towel so you don’t damage it or your floor.

Note: You have to turn off the water, but you are more likely to get your hands and tools wet.

Also: Set the tank lid on a towel so you don't damage your floors or get them wet.


Next, you need to drain the cistern. If you’ve switched off the water supply (and your toilet flush still works), simply flush the water out. Otherwise, lift the toilet flapper to drain the water. The flapper is at the bottom of the cistern and you need to look for a chain that connects the handle to the flap. Pull the chain up to lift the flapper so the toilet flushes. 

Tip: Let the water drain completely so you have a clean workspace.


After the cistern is drained, undo the chain attached to the handle - this is what lets you flush the toilet. Undo the clasp of the chain at the end of the metal or plastic lever that connects to the toilet handle.

Tip: Hang the clasped end of the chain over the side of the toilet so it's easier to find and reattach later on.


Now that it’s unchained, you need to remove the mounting nut that holds the handle in place, it’ll be either metal or plastic at the top of the cistern, on the inside. Try twisting the nut by hand to see if you can loosen it or use a pair of pliers. Unscrew the nut, as well as the black O-ring if it isn’t attached, and slide it down the lever to remove it.


Then, now that the handle is detached from the chain, pull the old handle out from the toilet through the hole where the handle used to be. Throw the old handle and lever away once you take it out from the cistern as your new handle will have a new lever, too.

Installing the New Handle

fit a new toilet flush handle


Check there is no damage when you unpackage it and then pull off the mounting nut and O-ring from the new handle. The rubber O-ring will already be attached to it. Unscrew the new mounting nut by turning it clockwise and then slide the nut down and O-ring the lever until they’re completely off.


Slide the lever into the toilet cistern, the reverse of how you took your old one off by guiding it through the hole for your handle to near the chain clip. Once the lever is in, the handle will fit against the side of the toilet cistern.


Put the O-ring and mounting nut back on and screw them in place. Guide the O-ring onto the lever first - if it’s not attached to the mounting nut. Then, do the same with the mounting nut until it holds the O-ring in place. When you reach the top of the lever - the back of the handle - tighten the nut by hand until it's tight against the side of the cistern.

Tip: Be careful not to overtighten the nut as you could strip it and make it more difficult to replace in future.


Attach the chain to the lever - there’ll be a few holes for this - so there's about 2.5 cm or an inch of slack. If you don’t leave this much slack on the chain, the toilet may not flush properly.


Turn the water supply back on at the valve and test your new toilet flush handle once the cistern has filled with water completely. Check whether the handle moves smoothly or if it gets stuck. If your toilet works fine, put the lid back on.

If the handle feels too loose, tighten the mounting screw. However, if your toilet doesn't flush at all, make sure the chain is attached to the lever properly.

How to replace a toilet button flush

how to replace a toilet button flush mechanism

This process involves some of the early stages from above - you need to switch the water supply off and then empty the cistern of water completely.


Unscrew the toilet flush button to remove the cistern lid - some may be attached to the valve itself - and then unscrew the toilet shut-off valve. Remove the float valve by unscrewing the fixing screw at the top of your cistern. Most cistern lids should lift off and have the button fixed to the lid by a nut.

Note: You wont need the back nut from the old button system as the new flush button includes one.


Unlike with a handle, you now need to temporarily remove your cistern. Once you’ve dried the cistern interior with a towel, unscrew the wing nuts underneath the pan that holds the cistern in place. Also, undo any screws that hold the cistern to the wall. Drain the remaining water and remove the watertight rubber seal found between the toilet bowl and the cistern.

Tip: clean the cistern and surrounding area, then, place carefully on a flat surface.

Affine Oceane Space Saving Toilet & Soft Close Seat


To remove your old button flush mechanism, you should be able to unscrew it by hand. There will be a plastic nut at the bottom of the cistern that holds the mechanism in place. If it’s tight, use some pliers to loosen it. Then, the old system should lift away. Give it all a clean afterwards as this will also give a good watertight seal.

You can reuse the seal you took off or replace it with the new one provided and fit the new button flush system - it may be called a valve in your instructions - inside the cistern.


Screw it in place and tighten the system by hand, you shouldn’t need any pliers.

Ceramica Milan Space Saving Toilet & Soft Close Seat


Place the new watertight seal between the cistern and the toilet pan and then you can refit the cistern. Just take care to ensure it is properly centred. Secure the cistern back in place, both against the wall and the pan.

Make sure the flush valve is turned to a position in the cistern where it won’t impede the float valve. If the float valve cannot move freely, the cistern won’t fill correctly. If your new button flush mechanism comes with a float valve, simply screw this into place.


Replacing the actual button is straightforward. Undo the mechanism by holding the back nut with one hand and then carefully unscrew it. Make sure the full and half flush rods line up with the paddles at the top of the flush valve, and then secure it in place.


Reconnect your water supply to the cistern and then switch on the water. Check for any leaks and, once you are happy, test the button flush unit.

If you're looking for further DIY advice and inspiration, you may find the following posts useful - How to Replace Basin Taps Step By Step - How to Measure for a Toilet Seat - How to Design a Small Bathroom.

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