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How do I change a top button flush valve in my toilet cistern

Welcome to this guide to replacing the top fixed, push button flush valve in your toilet cistern.

Below you will find  step by step instructions on how to change the flush valve, and a list of toilet manufacturers that this top fixed, push button flush valve from FlushKING wil fit.


If the toilet in these instructions, or video does not look exactly like your toilet cistern dont worry, the mechanics inside are all very similar.Find out about our Next Day delivery service

  • Fits all toilet manufacturers below
  • Dual flush will save water
  • Saving water will save you money if on a water meter
  • More reliable than old syphons
  • Easy to fit
  • Internal overflow, removing the need for external overflow pipes.
TowelPlumbers GripsFlat head Screwdriver

Tools you will need

You will find that FlushKING products are simple to fit without tools, however you will need to have tools ready to remove the old valve and cistern from the toilet. You will need a pair of grips, a flat head screwdriver and a cloth or towel (to protect your toilet seat & Pan) 

If you are looking to replace just the flushvalve then you will need one of the two products below. You can check what product you need by looking at your existing cistern and identifying where the flush is currently placed.

Type of toilet cistern Product you need Type of toilet

Top fixed button

Any toilet cistern lid with flush button on the top & centre.

Top Push Button Flush Valve

Top Press Dual Flush Valve

This flush valve will fit most top push flush button cisterns. It is recognised by the fact the cistern is fitted directly to the top of the toilet pan, and has a push button on top of the cistern lid as pictured left.

Lever flush cistern

Any toilet cistern with a lever flush in any of the positions highlighted.

Flexi Mount Dual Flush Valve

Flexi Mount Dual Flush Valve

This flush valve will fit most lever flush cistern, and with its fleximount cable the flush button can be placed wherever the flush lever used to be. This is also the case with concealed cisterns that may be fitted inside cabinets or stud work with abutton on the fascia our countertop.

It is a good idea, while you are removing your toilet cistern to consider changing your fill valve at the same time, as removing the cistern isnt a job you want to do regularly! Below are the productss you would need to change the flush valve and a fill valve, the fill valve is in two formats, bottom fill and side fill. You can check what type of fill valve you need by looking at your existing fill valve and where it protrudes from the cistern.

Type of toilet cistern Product you need Type of toilet

Top fixed button

Any toilet cistern with a water supply on either side as highlighted.

Side Entry Fill Valve

Side Entry Fill Valve

This fill valve will fit most toilet cisterns where the water supply connects to the cistern on the side , wherether the hole is on the left or the right.

Bottom entry fill toilet cistern

Any toilet cistern with a water supply connecting at the bottom of the toilet cistern.

Bottom fill valve, adjustable with brass shank

Adjustable Bottom Fill Valve - Brass Shank

Cisterns that have the water connection connecting on the bottom of the toilet cistern will use bottom fill valves. The example used here is fully height adjustable, and has a robust brass connection shank. You can also use the adjustable bottom fill valve with plastic shank if you are looking for a cheaper alternative. And if you cistern is not limited on height, you can also opt for the basic standard bottom entry fill valve which is plastic shanked and non-adjustable in height.

Step by Step

Turn off the water Step1: The first job with any plumbing is to turn off the water supply, hopefuly you will have an isolating valve next to your toilet cistern, otherwise turn it off at the stopcock, which can usually be found under the kitchen sink and looks like an old brass tap. Once the water is turned off, remove the bulk of the water from the cistern by simply flushing it. Once you have done this you can undo the pipe connector with your grips on the bottom or side of your cistern supplying the water to the fill valve.

Remove the lid from your cistern and take out the old push button. Step 2: You will now need to get into your toilet cistern to remove the remaining water and the fixings holding it to the wall and pan. Remove the flush button from your old valve, this may require unscrewing whilst holding the buttons down, as it may be fixed to your old flush valve, however, most lids should lift off and have the button fixed to the lid with a backnut. This back nut should undo by hand with no problems and you can remove the button from the lid and clean round the hole in the cistern lid ready for the new button. You wont need the back nut from the old button as the new button is a complete set.

Towel out any remaining water in the cistern into the pan Step 3: You will need to use a towel to  towel out any remaining water from within the cistern to avoid making a mess and to access the screws holding the cistern onto the pan. You will now be able to see two screws at the bottom of the cistern holding it to the pan, which have a pair of wing nuts underneath the pan. Also, you should see two screws at the top of the inside of the cistern holding it to the wall. ( I have suggested a flat screwdriver but these may be crosshead screws, depending on how long it was fitted)

 Undo the screwsStep 4:  Now you need to remove the screws in the bottom off the cistern by placing your flat head screwdriver into the slot and turning the wingnuts under the pan to loosen. If the wingnuts are too tight, spray with WD40 and leave for a while, then use your grips to try to loosen. If this fails you will need to carefully cut off the nuts. Once you have removed the bottom two screws, remove the two remaining screws at the top, back of the cistern fixing it to the wall. make sure to set aside all fixings as you will need them when putting it all back together.

Carefully lift the cistern away from the pan and lay it on the toilet seat covered with a towel to protect it. Step 5: Carefully lift the cistern away from the pan and lay it on the toilet seat covered with a towel to protect it. You should find a large black rubber or foam washer between the cistern and pan, if this has not perished you can reuse this but it is advisable to replace it now while you can. On the bottom of the cistern you will see a large plastic back nut which is securing your old flush valve into the cistern, this should be hand tight, however use your grips if needed to undo this nut and your old flush valve can now easily be removed. While you have the cistern off, also check the two bolts that secure the cistern to the pan are sound and fully tightened to the cistern.

Insert the new, FlushKING valve into the cisternStep 6: Make sure the inside and outside of the cistern is clean around the seat of the valve, this will make sure you get a good watertight  seal around the hole. Place the new FlushKING flush valve into the hole, ensuring the rubber washer is the right way up to fit the hole as it has two different sizes catered for. once in place and the rubber seal is between the valve and the inside of the cistern, tighten up the large backnut hand tight untill you cant turn it any more. You should not need to use grips as the washer will seal when had tight. 

Carefully lower the cistern back into place Step 7: Carefully lower the cistern back into place, ensuring you have replaced the black rubber or foam donut washer between the cistern and the pan. Once back in place you will need to tighten back up the two wing nuts on the bottom a little at a time to ensure an even amount of pressure is applied to the connection. You should now carefully nip up both wingnuts with your grips. Now replace the two wall screws at the top, back of the cistern to fix it to the wall. If your bolts and wingnuts are no good, you can use the flushking cistern fixings pack available here.

 Align the valve and adjust the flushStep 8:  Make sure the flush valve is turned in the cistern to a position whare it will not impeed the fill valves float as if the float cannot move freely it will not fill correctly. You can now set the required amount of flush for your full and half flush levels, and this is crucial to get right to save the most water you can whilst removing the waste in the pan, you can adjust this as many times as you want till you are happy. Instructions on setting the flush levels are in the box with the valve, but it is a simple slider on the valve.

Place the new button on the cistern lid Step 9: Replacing the button couldnt be easier, take off the back nut and place it in the hole making sure the full and half flush rods line up with the paddles at the top of the flush valve in the cister, and secure in place with the back nut. If the rods on the button are too long for your cistern, they can be removed and cut down to the correct size for your cistern. once you have cut them to size and positioned them correctly you can replace the cistern lid.

Connect the water supply, test for leaks and test flushStep 10: Now it is time to connect your water supply back to the cistern, switch on the water and check for any leaks by running your fingers over every joint you have worked on. Once you are happy all is dry and there are no leaks, test the flush unit by pressing one button, refilling and then the other button.



Fits all these toilet manufacturers cisterns

Twyfords logo Fits most Roca Cisterns Fits most Ideal Standard Cisterns Fits most Armitage Shanks cisterns Fits most Ideal Cisterns Fits most Shires cisterns Fits most Lecico cisterns Fits most Macdee cisterns Fits most Thomas Dudley cisterns Fits most duravit cisterns Fits most Vitra cisterns Fits most Bauhaus cisterns Fits most Eastbrook cisterns Fits most Rhoper Rhodes cisterns Fits most Bristan cisterns Fits most Hudson Reed cisterns


Did you know?

Levels of Water StressThe Environment Agency has developed a methodology for identifying and classifying relative levels of water stress in water company areas in England. The Government has used this map to designate areas of serious water stress for the purpose of accelerating water metering.

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