In this guide we will explain how to replace the Catis-type toilet flush valve, an essential component for the proper functioning of the drainage system in external flush cisterns. In many cases, in fact, drain malfunctions are attributable precisely to the Catis unit or the float.
Let’s see in detail how to proceed with the removal of the old Catis flush valve and the installation of a new one.
Index:
- What a Catis toilet flush valve is and what it is used for
- Catis flush valve replacement
- Catis replacement video guide
- Why you should replace the Catis flush valve
What a Catis toilet flush valve is and what it is used for
The Catis flush valve is an essential mechanical component for the operation of ceramic flush cisterns. It is a drain siphon that regulates the water flow when the button is pressed, ensuring effective and controlled emptying of the cistern.
The toilet flushing system works as follows:
- Button pressure: the button exerts pressure on the Catis battery valve, which is a spring cylinder.
- Activation of the flush: the valve lifts the piston of the coil and the water in the cistern is released into the toilet.
- Filling the flush cistern: once the water is released, the float drops and opens the water inlet, refilling the cistern to the preset level.
Catis flush valve replacement
In addition to managing the release of water, the Catis flush valve also performs a hydraulic sealing function, preventing leaks and ensuring that the tank is filled correctly. Over time, wear on the seals or limescale build-up can impair its efficiency, making it necessary to replace the entire assembly to restore full drain functionality.
Let’s find out together what steps to take to correctly replace the Catis flush valve.
1. Shutting off the water and emptying the flush cistern
The first step is to shut off the water flow and empty the cistern completely by pressing the drain button. Ceramic flush cisterns are connected to the plumbing system via a special tap, the tap for toilet flush cisterns.
2. Removing the old Catis-type flush valve
We then disconnect the small copper tube of the exhaust button from the Catis flush cistern, unscrewing the small bolt that blocks it.
Next, the screw that anchors the Catis unit to the ceramic flush cistern must be unscrewed. The operation involves two steps:
- Loosening of the lower ring nut locking the drain pipe
- Unscrewing the upper ring nut of the coupling screw, preferably using a socket spanner for a firmer grip
Once the screw has been removed, it will then be possible to remove the old Catis flush valve from the ceramic flush cistern.
To make it easier to remove the gaskets and the old fastening kit, which will be replaced with the new one supplied in the package, you can tilt the sleeve slightly.
3. Installing the new Catis flush valve
In the fixing kit included in the package of the replacement Catis unit you will find the following components:
- A fixing ring
- Three gaskets (two round and one square)
- A 30 mm connection screw
- A protective ring
- An additional conical gasket
Before inserting the new Catis unit into the toilet flush cistern, therefore, the drain pipe must be prepared by positioning the components in the fixing kit. This is the recommended assembly order:
- Insert the ring nut
- Position the square gasket
- Insert the connection screw with the ring nut facing upwards
- Add the two round gaskets
- Insert the protective ring, which serves to prevent damage to the ceramic cistern
Once this step has been completed, the drain pipe must be repositioned so that it matches the hole at the base of the flush cistern and, after positioning the conical gasket on the siphon connection (with the tip of the cone pointing downwards), the new Catis must be inserted.
Catis replacement video guide
We have also created a detailed video tutorial on the Elettronew YouTube channel, showing step by step how to replace the Catis flush valve.
Why you should replace the Catis flush valve
Replacing a Catis-type flush valve is an operation perfectly within reach of anyone with a minimum of manual dexterity and who can handle basic plumbing work. By precisely following the steps described above, it is possible to restore the functionality of the drain in just a few minutes.
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