Home Improvement

How to Fit a Mixer Shower

So, you’ve decided to give your bathroom a mini-makeover with a new shower mixer. Awesome – a new unit can make all the difference both visually and practically. Now, you’ve probably started asking yourself questions like…

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“How do you install the thing? It’s got to be difficult. ” 

“What about the tools – God knows how many instruments I’m going to have to buy…”

“Can’t I get someone to install the mixer for me?”

Calm down – it’s not that hard, especially when you’ve got us to help you out. In this article, we are going to discuss everything you need to know on how to plumb in a mixer shower. But first, we have to answer the question…. 

What is a mixer shower?

A mixer shower combines hot and cold water in a valve, which is then transported to the showerhead – it’s simple as that. Mixer showers are suitable for both low and high-pressure water supplies. Note that this plumbing part won’t increase the low pressure of water flow. 

Types of shower mixers

Different types of mixer showers require specific installation methods. What works for a push-on mixer, for example, probably won’t for a manual one. With that being said, here are the most popular types of shower mixers that you can find on the market:

  • Push-on mixer shower. If you are looking for a mixer shower that is easy to install, buy a push-on model. This option is perfect for people who aren’t planning on changing the plumbing unit any time soon. In order to install the mixer, all you have to do is attach the shower head and hose to the old bath faucet. Then, you just adjust the temperature of the shower using the bath knobs that you already have installed.
  • Bath/shower mixer. You can see this shower mixer model in most households. Typically, the showerhead is attached to the bath faucet and the same applies to the hose. There is either a switch or an ordinary knob there, which is used to direct the water flow towards the showerhead or to the bath faucet. You set the water temperature by adjusting the hot and cold water knobs, similarly to the push-on model. In terms of the installation process, setting up a bath/shower mixer is easy. You just have to install the device in a unit with a preexisting bath faucet. 
  • Manual mixer. A manual mixer is used when you don’t have a bath faucet, which means that the water is directed only towards a showerhead. With this type of unit, the temperature of the water is adjusted by a single knob that you turn circularly. Most of the times, the showerhead and the hose are built into the bathroom wall. You’ve probably figured by now that all of this means that the installation procedure will be a lot harder. The process involves connecting the hot water pipes to the unit and then attaching the hot and cold water supply parts to the mixer shower – it’s a lot. 
  • Thermostatic mixer. Thermostatic mixer models are a whole another story – they are a lot different than the options we described above. This mixer model is a bit tougher on the budget, making it expensive to install, as well. Similar to the manual option, the showerhead and the hose are built into the wall. Also, the hot and cold water supply parts are attached to a single valve. As the name suggests, this mixer model has a thermostat that regulates the temperature of the water, which makes them more expensive, as well. And as for the installation process…

How to fit a mixer shower

Time needed: 45 minutes.

Note that our article will focus on how to install a thermostatic mixer shower because this type of unit is the most complicated to set up.

  1. Turn off the water supply and remove your old mixer unit.

    Before you start dismantling the item, double-check if the hot water feed is placed on the left and the cold one – on the right.

  2. Get the old mixer out of the way.

    You can save it for a potential emergency plumbing situation.

  3. Prepare your tools.

    Once you have everything layout the parts you are going to use for the project. Ensure that you have different sized open-ended wrenches at hand.

  4. Screw the S union connectors to the fittings on the wall.

    Ensure that you seal their thread with PTFE tape by wrapping it in the tightening direction. The connectors need to extend around 42 mm. Apply a silicone seal between the wall and the connectors. Make sure that there is a 150-mm space between the centres of the connectors. Double-check if they are level and adjust the parts if required. Then, attach the escutcheons by screwing them onto the S union connectors.

  5. Secure the new shower unit.

    Before you install the mixer unit, make sure that the filters under the blue and red caps are facing with their rounded side inwards. Tighten the mixer well. There’s no need to apply any additional seals. Still, note that the nuts can’t touch the escutcheons.

  6. Test the thermostatic mixer.

    You can do this by measuring the temperature of the water with a thermometer. If the water temperature is not in line with the temperature marker on the unit, you’ll need to adjust the unit. Before you do this, you must close the water evacuation outlet and then, remove the cover on the mixer handle. You can accomplish this with a flat-head screwdriver. Once you’ve loosened the screw, you can remove the handle. 

  7. Adjust the thermostatic cartridge.

    Once the handle is removed, turn the notched black part of the unit and set it to 38°C. After that, put everything back together, set the hose in the right position, and finally screw the end onto the mixer unit. That’s it – you are done. 

Need a professional to fit your new mixer shower?

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Doing plumbing work around your house is hard, requires a lot of skills and a long list of expensive tools. And let’s not forget the fact that if something goes wrong, you can be left with a serious plumbing issue and a dent in your pocket. With that in mind, why not leave your plumbing tasks to the hands of the experts?

Fantastic Services offers professional plumbing services for any project and situation you might have. Anything from boiler installation to unblocking a drain – you name it, and the professional plumbers will do it.

Our services are fully insured, the experts bring all the required tools and equipment for the job, and you can book us for any day of the week! Now, drop that wrench and contact Fantastic Services today to make your plumber service appointment! 

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  • When doing any kind of plumbing work around your home, always turn off the water supply, first.
  • Thermostatic mixers are quite practical, but happen to be on the expensive side. 
  • This installation project involves a lot of different sized tools and instruments that you may not have at home. We advise visiting your hardware store before you start with the plumbing project. 
  • If you find yourself struggling with installing the mixer shower, we advise calling a professional plumber. 


Did you find our article on how to fit a mixer shower helpful? Please, share any questions or plumbing tips in the comment section below!

Image source: Oleg Shishkov/shutterctock.com

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