How to replace an Electric Shower - Full Instructions

How to replace an Electric Shower

How to replace an Electric Shower
Table of Contents

There are many reasons most of us want to replace our current electric shower.  Maybe the heating element has given up, the shower has sprung a leak, or even your after upgrading your old Electric Shower to a newer more powerful model.  Replacing an electric shower should take no more than 30 minutes.

Broken Showers > Many people I know call the Manufacturer who will try and allocate the part required to get the shower working again.  This can be an extremely cheap way to fix a broken shower so it's definitely worth giving your shower manufacturer a call.  However in my case, the possibility was 2 parts, its a fact of life that if I purchased part A it would be part B that would fail.  The total cost of the 2 parts were about £10.00 short of a brand new shower - with onsite warranty - so it made perfect sense to order a brand new electric shower online.

Tip: If you are unsure about any of the process please contact a Plumber & Electrician to carry out the work

Well fear not, the process is quite easy providing you try and follow the simple steps outlined in this guide below.  The key to replacing any electric shower is split in to parts, the first being "Why do you want to replace the shower?".  For most of us, replacing an old shower because it is no longer performing like it did (which covers leaking pipes, heat fluctuations, discolouration) will add a new lease of life to daily task of washing yourself in complete harmony.  There really is nothing worse than a shower which fluctuates between too hot and too cold temperatures.  For the rest of us, who just want to replace a shower for more features, higher wattage etc, then the process is still the same and can be extremely quick if you follow the simple guide below.

If you have an existing wall covering such as tiles, boarding etc, and want the least amount of disruption to your current décor, its worth checking with the manufacturer of your existing shower to find out which product has the same backing design.  The same backing plate means that your new shower will fit snugly into the existing area without too much fiddling around, and 9 times out of 10 the same screw holes can be used. #win

What Tools do you need to replace an Electric Shower?

Replacing an electric shower is quite a straight forward task and only really relies on the following items:

  1. Screwdriver (+ & -)
  2. PTFE Tape
  3. New Shower (of coarse!)
  4. Plyers (for unscrewing the water pipe nut)

Instructions for replacing an Electric Shower

First off, I want to show you an electric shower.  The concept is simple.  Cold water enters from 1 end of the shower, it then passes through an electric water heater and comes out the other end nice and warm.  The wattage of the shower affects how fast the heater heats the water and in some cases the speed at which the water is pumped through the heater element. The dial on the front of the electric shower controls the temperature of the water, the hotter the temperature the slower the water flow (higher wattage showers do not suffer as much with this).

You must turn off all power to the shower.  Usually the shower is on a separate circuit (well it should be - if not - contact a qualified electrician to do this for you), so by flicking the RCD switch / removing the fuse, you know that your not going to get zapped!  Its also a good idea to turn the shower pull cord to the off position - this is like a double safety check to ensure there is definitely no electricity making its way to the shower unit.

You must turn off the water to the shower.  If your shower has been installed fairly recently, you may have an isolating valve in the floorboards / loft.  Check for this first.  However if like me you don't have one, then turn off the water at the stop tap.

So, now we are safe, you need to remove the shower cover.  To do this locate the small metal screws usually placed 2 at the top and 2 and the bottom.  These screws just hold on the front electric shower panel - so make sure you either have somebody to catch the falling panel, or pop a blanket / dust sheets in your shower area as not to damage any walls / trays etc.

Once the cover has been removed, I always think its best practice to take a photo of the insides before you start disconnecting things.  This helps when popping things back together, in most cases you will never need to refer back to the picture, however for those of us who have hectic lifestyles - being pulled away from one job to do another is a regular occurrence!  To prove it, here is my photo i took on an old mobile phone when I replaced our electric shower:

Ok, now the fun part.  We are going to disconnect the shower from the mains, disconnect the water, and remove the backing plate from the wall.  I have numbered the process in the diagram below.

Make sure that once you pull the shower base plate away from the water pipe you have some form of floor covering.  Although the water is disconnected (point 3), there is still some water in the pipe - so brace yourself.  Also, be sure you pull the shower base plate in the opposite direction to the pipe.

The water pipe actually sits around 2" inside the electric shower unit , so if you pull the base plate to the side this could cause the water pipe to buckle - and add a significant plumbers cost in repairs!


Now you have your old shower off the wall, its time to take a look at your water inlet pipe.  You will notice that around the pipe there is a small copper "ring", this is called an olive.  The olive seals the joint between the electric shower unit, and the pipe.  Although most plumbers will recommend replacing the olive, in most cases the olive will have become so attached to the pipe - it would need cutting.  This will obviously cause the backing plate to be in a different position where new holes need to be drilled slightly higher.

For me, the olive was in tact, but as above was stuck into the copper pipe.  With our type of plastic wall boarding, it wasn't a very good option to remove it, so I wrapped a load of PTFE tape around the existing olive before offering the new shower base unit to it.  This worked, and worked very well and saved me a whole load of time.  Once connected back into the shower, just tighten the nut - not too tight as this will have a negative effect and break the olive seal.

Once you have fitted the new base plate, and reconnected both the water inlet pipe and electricity cables (use the photo you took for how to wire these in the correct places), its now time to replace the electric shower frontage. To do this, like above there will be 3/4 little screws.

Done!  Well done, now you can turn your electricity and water back on and test the shower.  If you notice any leaks coming from the bottom of the shower immediately turn the shower and electricity OFF, remove the face plate and tighten the nut at the water inlet valve.

Known problems after replacing an electric shower

  1. The shower does not turn on at all
     a) Check the cable connections inside the shower, make sure the screws in the junction box are tight and making a good connection
     b) Ensure the fuse has not blown - if this has happened check the cables in point a.
     c) Make sure the show pull chord is on - if the LED is lit, then the problem is at the shower unit - not the fuse box
     d) Make sure the water is turned on - some showers will not operate without a flow of water.
  2. The water does not heat up
     a) Check the wiring as per point 1 a,b,c
     b) Ensure the water pressure is high enough - make sure the stop tap is full open
     c) Leave the shower to run for 5 minutes - some showers are filled with an anti freezing liquid when shipped and may take time to be completely out of the system