How to replace a shower mixer tap by yourself

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  • OVERALL DIFFICULTY INDEX: 4/10
  • IF YOU HAVE NO TOOLS, YOU PAY $30 TO GET THEM FOR THIS JOB
  • IF YOU HAVE NO EXPERIENCE YOU SPEND 2 HOURS TO CARRY OUT THIS JOB (see below)
  • NO SAFETY ISSUES RELATED TO THIS TASK
BEFORE YOU START
-Since usually mixer taps do last a matter of 15 to 20 years, it is probable to encounter some trouble behind the tap like corroded water outlets in the wall which could extend this intervention to 3 to 4 hours if you have no experience.
BEFORE
AFTER
DISCLAIMER:
Our pictorials are of informative nature and do illustrate works carried out by ourselves at our own premises for our own use and satisfaction.
Readers who envisage to carry out similar works inspired by the below method shall do this at their own risks and liability.

Wondering if you can remove and replace the shower mixer yourself?

YES, replacing a shower mixer is a quite easy intervention, requiring no works on piping or plumbing installations, simply removing and refitting a new mixer tap, which can be done by anyone who has a bit of patience, little tools and who read our below details pictorial!
This applies to any kind of shower mixer with or without a visible shower bar.

Preparatory works for the shower mixer replacement

Shut off the cold and hot water supplies of the shower mixer.
This shower mixer aged 21 years and its middle handle, the one that shifts the water flow to the shower head, got stuck.
At this age, it is not recommended to replace the mixer cartridges only, rather proceed with the complete mixer replacement.
Below pictures will also show the extents of the damages resulting from an initial poor installation.
TIP: Do not attempt to renew or repair an existing mixer of more than 20 years of age. This is totally not recommended as it is time consuming, requires some seals and grease that you don't have and will lead to the renewed mixer having a short lifetime of a couple of years. Replacing the cartridges alone won't solve your problem, unfortunately.

How to remove the old shower mixer tap from wall

You need to have 12" monkey pliers and a 30 mm spanner.
Simply unscrew the flexible shower hose then use the spanner to unscrew the two chrome plated nuts of the mixer.
​Remove the mixer.

Trying the new mixer tap before installing it to your shower wall

Unpack your new mixer which is supplied inclusive of:
  • The mixer 
  • Two chrome plated wall outlet covers
  • Two eccentric 1/2" - 3/4" adapters
  • Two 3/4" gaskets
Try the new mixer on the existing male threads.
You'd be lucky if it fits exactly on the same outlets in which case you just have to carefully tighten the mixer nuts and that's it!
Most of the time the distance between the cold water and hot water tap connectors will not match the one of the previous mixer as shown in the below picture:

Preparing for the new shower tap installation 

Start by unscrewing the chrome covers for removing them completely.
In this case, the holes inside the covers were not sealed by the plumber when installing the previous mixer, one can see the extents of the corrosion that has seriously damaged the water outlets. Such corrosion also led to the fracturing of the porcelain tiles.
No need to panic if you face the same scenario...and check our specific page on how to replace the embedded water outlets.
Start by holding again the new mixer in front of the male threads for evaluating how much these have to be brought closer (or eventually farther). Follow the instructions in the below pictorial:
1- Compare the mixer nuts to the existing male threads. In this case, the new mixer has a shorter distance between its connetcors.
2- Using your monkey pliers, equally rotate each eccentric in opposite directions i.e. the left one clockwise, the right one counter clock wise for reducing the distance between them.
3- This could be quite difficult with the pliers, if so, use a size 13 spanner and extend it with another spanner to increase your force.
It is very important to equally adjust each of the threads for the mixer to remain horizontal.
Use a measuring tape if needed to check the distance to the shower tub.
Keep trying the mixer and fit it in temporarily to make sure the nuts do turn by hand easily.
Notes:
  • This is the simplest way of re-adjusting the existing water outlets to the new tap but is not guaranteed as it depends on the type of sealant that was used by the plumber and the state of corrosion of the wall embedded fittings.
  • In general, if you succeeded in rotating the eccentrics, then you just need to check for leaks as shown below. Eventually, completely remove the eccentric adapter, use some Teflon tape and refit it.
  • The worst case scenario would be that the wall embedded outlets are so corroded that you need to replace them; this requires the removal of a few tiles and considerably complicates your intervention but remains within the medium difficulty DIY works that average DIYers can do.
Now plug each of the water outlets and open the water supply to make sure there are no leaks (left image).
If a leak is found, remove the adapter, seal it with Teflon and fit it again.
If not, clean the wall outlets as much as you can with a brush and a screwdriver and spray the corroded parts with WD40 at least or better, a corrosion stopper. 
TIP: in case your tiles where cracked in surface, use some super glue to refit the largest fragments. You can later apply liquid porcelain chip repair on the remaining surface. 
Clean well the threads with a brass wire brush, remove any remaining gasket with a cutter blade, seal the holes with silicone and apply one drop of oil to the thread:

Fitting the new mixer tap and refitting the shower head

Try the covers that were supplied with the tap and use them if the space between the tap and the wall is enough.
If not refit the previous covers after thoroughly cleaning them.
Place the supplied seals in the tap nuts before fixing and carefully tightening these.
Complete the installation by refitting the shower head.
Clean all with white vinegar.
TIP: If you want to fit the new covers for sure, then you need to try them at the beginning and eventually take out the adapters and re-screw them in, just enough to leave sufficient gap between the wall and the mixer nuts.

See all our taps and mixers tutorials: