How to Fit a Shower Mixer Tap — UK Bathroom Guide
Shower mixers fall into two families: bath-mounted (2-tap-hole) and wall-recessed. Both use the same 15mm hot/cold tail principle. Here is the UK install method.
Step-by-step method
1. Isolate hot and cold
Under bath usually. Combi-fed showers can share the boiler tails.
2. Remove old fittings
Undo tap connectors on tails. Free the tap body from the bath rim (two backing nuts).
3. Fit the new mixer
Rubber seals top and bottom. Backnuts finger-tight, then quarter-turn with a spanner.
4. Connect tails
Copper 15mm tails or braided flexis to isolators. PTFE on threaded joints only.
5. Test at full pressure
Open both isolators, run mixer 5 minutes hot and cold. Check under bath with a torch for weeps.
Frequently asked questions
Do I need a thermostatic mixer?+
Highly recommended for combis and unvented systems. Prevents scalding when someone flushes the loo. £40 uplift over manual.
Bath centres for shower mixer taps?+
UK standard is 180mm hole-to-hole centres. Check yours — Continental taps are 150mm.