A thermostatic mixer shower is an essential part of any bathroom. They are safe, convenient and economical, while also protecting you and your family from the risk of scalding. A thermostatic mixer maintains a satisfying temperature for the duration of your shower. It protects you from any sudden changes in the water supply, so even if somebody else in your house flushes the toilet or turns on the kitchen tap, the temperature will always remain the same.

Want to install or replace a thermostatic mixer shower yourself? The following is a list of tools you’re going to need…

  • Drill and a drill-bit – for drilling into your tiles
  • Detector – to make sure you’re not drilling into any pipes
  • Spirit levels
  • Tape measure
  • Rubber mallet
  • Screwdriver 
  • Allen key
  • PTF tape


And remember to always double check your parts included for your shower.

This particular model has: 

  • The Thermostatic Mixer head
  • Main bar
  • Large shower head
  • Hose
  • Handheld shower head
  • Washers 
  • Various different fixings
  • Instruction manual – for guidelines on how to install your mixer shower

To start, you will need to remove any wall covers. These are quite easy to remove, all you need to do is unscrew them anticlockwise.

You will see a plate behind these covers, which are screwed into the tiles. These are connected to the 15mm water pipe behind the wall tiles. 

Once this is complete, screw in your new wall covers. 

Before you start to install your new thermostat, you must firstly turn your water on to clear any loose debris inside the pipework.

On the back of the thermostat you will see a hot and cold symbol, as well as the compression connections for your water pipes.

Place this in line with the wall covers and hand tighten the compression nuts clockwise until they start to bite.

Once you’ve tightened them as far as they can go by hand, apply some gaffer tape around the nuts before using your spanner. This is because, whether its a matte black finish, or chrome or satin finish, there is a risk you can scratch the surface with your spanner. If you don’t have gaffer tape, a cloth will suffice. 

Just over a quarter to a half a turn with your spanner should be enough to tighten the compression nuts. You can always check that this is central with your spirit level.

The next stage is to install the sliding rail, this has to be connected to the tiles. Take a spirit level and find your centre point, then make your markings. With a larger spirit level, find your second centre point for the top of the rail. 

Once you have made your measurements, remove the dust cap on top of the mixer shower and also the protection cap at the bottom of the sliding rail. Screw the sliding rail into the mixer shower, then using a small boat level, transfer the centre point to your tiles. 

Now the rail is connected, you need to install your bracket, which mounts to the wall and holds the rail in place. Check the bracket is central with a spirit level, then using a marker pen, draw small dots along all 4 corners of the bracket. Place another sprit level and draw two lines diagonally from dot to dot. This will act as your drill point. 

Before drilling, pop your dust cap back on the mixer shower and check there are no pipes behind the tiles using your detector.

Tilt the drill on an angle, start the drill, and press the nib against the surface. Once it starts to cut into the tile, raise it up and drive the drill in at 90 degrees.

Then you can apply your 6mm plastic rawl plug. Give this a gentle tap with your rubber mallet, so it doesn’t break the tiles.

Place the screw into the back part of the bracket and start to hand tighten this into a wall. Then you will need a normal screwdriver to finish this up.

Double check that it’s level, then you can wipe away the debris from the drilling and place the shower bar into position, screwing the nut onto the top of the thermostat. 

Then slide the one section of the bracket into the wall mounted bracket you’ve just fitted. You’re going to have to tighten the nut up at this point, so apply a bit of gaffer tape to the rail so you don’t damage the surface with the spanner. Then using an Allen key, tighten the screw that holds the brackets together.

Finally, there is the shower head. On the back, take off the plastic cap and you’ll see a rubber filter. Screw this into the rail and use the adjustment handle if you need to higher the shower head.  Then you can put the washer in the flexible hose and attach the handheld shower. Apply another rubber washer to the other end of the flexible hose, then connect that to the thermostatic bar. 

And that is your thermostatic mixer shower now complete. For the full ‘how to’ video, follow the link below to our YouTube channel and see each step in action.  

But, if you just want to know more about the products we’ve been using, why not visit the Tile Mountain website – www.tilemountain.co.uk