How To Replace A Mira Element — Trade Guide
The Mira Element is one of the most-fitted thermostatic mixer showers in the UK. Whether you're replaceing one for the first time or swapping like-for-like, this trade guide covers the exact sequence — including the isolation and pressure-test steps DIY guides skip.
Step-by-step method
1. Isolate water and power
Turn off the mains stopcock and the electrical supply at the consumer unit — the Mira Element runs on a 40A or 45A dedicated circuit. Prove dead with a voltage tester.
2. Remove the existing unit
Undo the front cover. Photograph the wiring in the terminal block. Disconnect the 15mm cold feed at the top. Unscrew the back plate.
3. Fit the new back plate
Mark and drill for the Mira Element back plate — use Rawlplugs into brick, or fixings into stud where possible. Feed the cold supply and cable through the correct entry points.
4. Wire and plumb
Connect the cold to the 15mm inlet using a service valve for future maintenance. Wire the Mira Element exactly as the diagram — L, N and Earth. Torque terminals to 1.5Nm.
5. Commission
Restore water, purge air, then restore power. Run for 90 seconds on low setting to prove flow and heat, then full temperature test. Fill in the warranty card.
Frequently asked questions
Does a Mira Element need Part P notification?+
Electric shower circuits in bathrooms are notifiable under Part P. An electrician must certify or replace like-for-like on an existing circuit.
What kW rating is best?+
9kW gives 5 L/min at 35°C rise (winter), 10.8kW gives 6 L/min. 8.5kW is fine for southern England, 10.8kW recommended for Scotland / Northern homes.
How long does a Mira Element last?+
7–10 years typical. Element failure is the usual end-of-life fault. Descale monthly to double lifespan.