A Step-By-Step Guide On How To Fit An Electric Shower

Have you just finished painting your bathroom or your bathroom tiles? Are you ready for more updates? Do you want to get a new shower or replace an old one? If you are looking for an easy to fit option that is also low cost, an electric shower is the answer! It can be a great choice, especially for busy households and can offer hot and steamy water any time of the day. 

Want to know more? Most electric showers come with thermostatic controls, so you can enjoy a safe and comfortable showering experience without worrying about the rest of the house’s water activity. Sounds great, right? Keep reading to find all you need to know about these shower wonders and a detailed guide on how to fit yours in your bathroom.

How does an electric shower work?

It works similar to an electric kettle. It gets cold water and makes it hot! Using electric heating elements, it gets cold water from the mains. There’s an element inside every electric shower that heats the water as it passes through. You don’t need to wait for hot water to be heated by a separate system like a gas boiler. You may control the temperature by changing the rate at which the water passes over the element. Some of them don’t have a thermostat. As a result, if the incoming water’s temperature varies, the one of your shower will too.

You can fit yours over the bath or in a shower enclosure. When deciding where to put it, make sure there’s enough room to remove the cover in case it needs servicing in the future. It comes with a showerhead, hose and a riser rail. Depending on the unit’s type, the water supply pipe could enter from the top or bottom, so ensure you have the right amount of cable coming out of the wall to connect it to the terminal block.

Water supply

Before you decide to install one, you should know that it requires cold water, mains pressure, and a decent water flow rate. That’s why it is essential to make sure that you have a suitable supply. A higher kilowatt shower, like a 10.5kW, may require 1.5 bar water pressure at 11 litres a minute. The most increased static pressure should be no more than 10 bar. Although this is high pressure, if you live near a water pumping station that needs to pump water up a hill, you may experience this pressure. In this case, you can install a pressure reducing valve.

With cold water tanks in the loft, some old houses only have a low-pressure supply upstairs – usually 0.1-0.3 bar. In these cases, you have to figure out the best place to tap into the supply so you can run a separate main cold water feed for the kitchen sink and the shower. A shower like this won’t work on a low-pressure supply, but there are specifically designed products for this situation, like a Triton T90xr pumped electric shower. It is essential that you can isolate the water source to the shower to ensure it can be serviced. You need to fit a 15mm isolation valve where it is easily accessible, so don’t hide it under floorboards or behind tiled walls. If you need extra help, you can always hire a plumber.

Electric power supply

An electric shower can draw up to 45 Amps of electric current, and it needs a separate supply cable and fuse from the consumer unit. You must install a 30mA residual current device (RCD) in the shower circuit. This could be a separate unit or part of the consumer unit. Most modern houses have 80 Amp or 100 Amp, but older ones may only have a 60 Amp supply to the entire house. Keep in mind that some large electric cookers also require a 45 Amp supply, so it’s worth checking whether you need to upgrade the housing supply. You can ask for more advice from a qualified electrician.

You should calculate the electric cable size based on the shower’s power, the length of the cable run and where the cable is running. When installing a new electric shower for the first time, it’s wise to future proof the installation and put in a line that’s suitable for a 10.5kW shower, even if you are only installing an 8.5kW one. That way, you can upgrade the power in the future without having a problem. This means you should be using a 10mm² cable in most cases. Don’t mind the installer saying it will cost a lot more than using a 6mm² one. If you decide to use a 10mm² cable, it will cost around another £1.50 extra per metre

The separate cable will generally run in the bathroom ceiling, and you’ll also need an isolation switch near the shower. These are usually 45 amp double pole isolating pull cord switches with a 3 mm minimum contact gap in both poles. Also, most of them have a red light to show when power is going to the shower.

The advantages of electric showers

Many homeowners these days, especially in busy households, consider them a much better option than those running from a large cold water storage tank. They ensure that a hot shower is always available to all your family members whenever they want one. You won’t have to wait around every morning because your partner has used all the hot water or having to shower at night to avoid that scenario. Find here the full benefits:

  • You can have hot water any time.
  • They are energy efficient, and you can save on energy costs.
  • They can help to solve the low water pressure problem.
  • They are available in a range of colours, sizes and finishes, so it’s up to your taste which one to choose for your home.
  • They come in a range of power options—from 8.5kw to 10.5kw—so if you want a stronger and hotter shower, you can choose the highest wattage.
  • Other water use in the house doesn’t affect their temperature.
  • Having a simple and intuitive temperature regulator allows you to adjust the water temperature easily, so it’s exactly how you like it.
  • They are available for a variety of different prices, ranging from affordable to exclusive.
  • They are easy to install and don’t require any extensive building work.

Preparation before your electric shower installation

Before you start fitting your new one, there are a few things you need to do first. Find here all the proper steps to preparing for your new unit.

Step 1: Pick a location

Choose a location for your shower close to the main cold water source and near a spot where you can install an independent circuit.

Step 2: Prepare the pipework

  • Get help from a plumber to ensure that your building’s plumbing system can accommodate a shower like that.
  • Run a single 15mm pipe from the cold supply near the storage tank to the wall where you’re putting the shower. 
  • Hold the unit in place and mark the position for the pipe entry and electrical supply cable. 
  • Make sure to use a pipe and cable detector to check for any hidden pipes or cables before drilling into the wall. 
  • Pass the pipe through the wall at the place you’ve marked. 
  • Place an isolating valve in the pipe, and put the correct connector for the unit.

Step 3: Provide the electricity supply

  • Drill a hole in your wall for the electric cable using a cordless drill. Make sure to check the manufacturer’s instructions to find a suitable cable’s size. This depends on the length of the run and the shower unit’s kilowatt rating. 
  • Run a cable from the unit position to a ceiling-mounted double-pole pull-cord switch. It is essential to have an on/off indicator, and you shouldn’t put it in hazard zones 1 or 2 as described by the IEE wiring regulations. 
  • As already mentioned, your shower needs its own dedicated circuit from the consumer unit, protected by an RCD. For safety, you should get an electrician to make the final connection.

Step-by-step guide: How to fit an electric shower

It’s now time to fit your new shower! We offer an installation guide to ensure you do the job right and avoid any problems in the future. It is crucial to keep in mind that you must install these products following the building regulations, and more specifically, the section of domestic electricals, called Part P. If you are just changing an existing shower with a like for like one, then you don’t need to inform building control. 

Step 1: Make holes for the shower unit

  • Hold the unit in the position you want it and mark the fixing holes with a chinagraph pencil. 
  • Use a masonry bit to drill holes at the marked positions. 
  • If you’re drilling into a tiled surface, use stick masking tape or a tile bit on the tiles to stop your bit from slipping. 
  • Fit wall plugs, and squeeze some sanitary silicone sealant onto each one.

Step 2: Screw it to the wall

Feed both the pipe and the electric cable through the unit’s backplate. Then use the screws to pin it to the wall.

Step 3: Connect the inlet pipe to the shower unit

Connect the inlet pipe to your shower unit, and with a pipe wrench, secure the compression fitting.

Step 4: Fix the cable to the unit

Fix the cable to your unit by connecting its neutral and live cores to the terminals marked ‘load’ and the earth core to the earth terminal.

Step 5: Fit the cover

Fit the cover following the manufacturer’s instructions. Make sure that the rubber seal is in place and fully tighten the water connection.

Step 6: Fit the rail

Make sure to put the rail high enough for your shower head not to dangle less than 25mm from the spill-over level of your bath, washbasin, shower tray, or bidet. If you don’t, dirty water might siphon back into your water supply.

Step 7: Connect the hose and handset

Screw one hose’s end to the handset, ensuring you include any washers supplied. Check everything is working correctly, following the manufacturer’s instructions before screwing the other end to your shower unit.

Step 8: Check to see that the electric shower is heating the water

Turn on the independent circuit and the water source. See if it is heating the water efficiently and quickly. Clean your shower glass, if you have one, and you are ready!

How much will an electric shower installation cost?

You can have a professional install yours or make it a DIY project. Keep in mind that in most cases, the installation can cost more than the shower itself. This might be worth it considering the difficulty of the project and the dangers hidden under the electrical work

If you have the experience needed and you feel confident to do it alone, go ahead. Here you can find the average cost, labour cost and even the price of a mixer, power, thermostatic, and digital shower so that you can compare.

Shower installation costsRange – LowRange – HighAverage labour
Electric shower£60£200£200
Mixer shower£50£150£150
Power shower£100£500£350
Thermostatic shower£120£200£200
Digital shower£350£600£300+


These days you can find high-quality electric showers, all at affordable prices. We are sure you are fascinated by their many benefits. The ease of their installation is the cherry on top of the cake. The only thing left to do is to get your own electric shower, one that fits your taste and bathroom’s style and start! Are you ready?

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