Replacing a Geberit Twico 1 Impuls 250 toilet dual flush valve

Replacing a Geberit Twico 1 Impuls 250 toilet dual flush valve

Geberit Twico 1 Impulse 250 dual flush valve

You find a Geberit Twico 1 flush valve in many Australian Toilet suites including:

Argent, Brodware, Catalano, Cotto, Duravit, Gemini, Ideal Standard,

Kohler, Laufen, Parisi, Pozzi-Ginori, R.A.K., Sangara, Stylus, Toto,

Villeroy & Boch and Vitra.

We sell the entire Geberit Twico 1 Impus 250 valve with all ancillaries including buttons, bridge and push rods here.  If your button is OK and you just need the body of the valve then click here for the alternate part.

Replacing the Geberit dual flush valve in the cistern (e.g. in a Duravit toilet)

Instructions are below but you can also watch it on our YouTube Channel.

When you buy it from us, it comes with a button (and once  you pop the packing out) you'll see the half-moon buttons. Then look inside the overflow tube and you'll find the rods for the button, a green and a black one. Black ones are the bigger one and it goes in the bigger hole. The green one goes in the smaller hole.

Adding the rods to the button for the Geberit Twico button

To remove the Geberit valve from your duravit cistern

What you have to do is to push down one button of the half moon buttons (the smaller one) and then just get yourself a little screwdriver or a knife, and pop it under the lip of the other button, and just lever that up. And it will come out with the rod. Then you can just leverage out the other one.  And that comes out with a rod too.

There's a screw head down below. So with a large flat screwdriver, you just undo that screw. And then the bezel will come out of the top of the cistern.  Don't try to remove the cistern lid until you have removed this screw.  Otherwise you may damage the valve.

Once you take the cistern lid off underneath you should have the bridge, which has the central hole (where the Bezel's screw was in). The bridge clips into the sides of the valve.  To remove this you will see the two little buttons on each side of the main unit.  You push those in at the same time, quite hard, and then pull the bridge up. 

And your final step is to split the valve by pressing in the two tabs near the bottom of the unit and pull up. 

Now you shouldn't need to take out this bottom section and that will stay in place. The original one should be okay, as long as it's not leaking.  You might also want to adjust the half-float position in the new unit before replacing.

How to adjust the half flush amount in your Geberit Twico 1 Impuls 250 toilet dual flush valve

In the main unit where you have removed the bridge you will see the half flush float inside when looking down from the top.  If you twist the half-flush float anticlockwise, so it unlocks you can then move it up or down into the position you want, and turn it clockwise to lock back in position. The higher you have it, the less of a flush you'll have on half flush. 

To install the Geberit valve from your duravit cistern

Push the new section with the half flush float back into place on the old bottom section.  

Turn it around until it's in the right position for the half flush and the full flush. You may need to adjust the overflow pipe on the side of the unit.  If you do need to change this then there is a locking system clip part way down that you push forward, and then the pipe is loose and you can pull it up to the right height and then click the clip back into place.

Then push the bridge into place, note that it will only go one way (as there is thicker leg of the bridge and a thinner leg). Make sure you get those right. It will push down like on a ratchet. And it should be pushed down to just below the level of the cistern lid.

Once you've done that, you need to put the cistern lid back on, put the rods in and cut them to size. So with the cistern lid back on you put the rods back in and you trim these flush with the top of the cistern.  So you can cut them with a pair of pliers. Where you've cut them the ends won't quite be round. So you get a pair of pliers and you just squeeze up the ends to make them as round as you can. But when you put them back in, the end that hasn't been cut should be facing up for the button. 

Screw the bezel in and then push the buttons in through there. Remember there's a correct hole for each one. The green one goes in the small hole. The black one goes in the large hole. 

What should the overflow pipe height be?

There should be just 25 millimeters from the top of the water to the top of the overflow (not less than that).


Some other reminders

REMEMBER, when replacing the flush valve, it is a good idea to also replace the inlet valve. These items have a similar lifespan and you don't want to be doing this job twice. Have a look at our inlet valves, they probably cost less than you expect. 

Also, for adjustment of your valve, have a look at our page explaining how they work. This will give a good idea of how to adjust them. 



Toilet manufacturers rarely make parts which look the same but are slightly different. Check the photos and dimensions and if it looks identical then it probably is identical.