How to Replace the Thermostatic Cartridge on a Mira Vision BIV (UK)
UK guide to swapping the thermostatic cartridge in a Mira Vision BIV shower valve. TMV2 compliance, part numbers, tools.
The part
Rebalance a scaling Mira Vision BIV by swapping the OEM thermostatic cartridge — restores TMV2 approval and 38 °C set-point.
Isolate
Isolate hot and cold at the built-in EasyFit valves or dedicated isolators. Drop the pressure by opening the outlet fully.
Swap the thermostatic cartridge
Undo the temperature handle grub screw, remove the escutcheon and pull the cartridge with the OEM extraction tool — needle-nose pliers will crack the Mira plastic housing.
Commission
Balance hot and cold to within 0.5 bar. Run the Mira Vision BIV at max flow for 3 minutes.
Verify max outlet temperature stays below 46 °C per BS EN 1111 by shutting off cold and reading the outlet.
Frequently asked questions
- How do I set the max temp?
- After fitting, run cold-only, then set the shroud to 38 °C, then hot. Rotate the stop-ring until 43 °C max is achieved at the outlet.
- TMV3 compliance?
- The Mira Vision BIV cartridge is TMV2 approved out of the box. For TMV3 (healthcare) fit the -HC suffix variant.
- OEM or aftermarket for Mira?
- For TMV2/TMV3 compliance always fit genuine Mira cartridges. Aftermarket voids the Vision BIV approval.
Browse shower spares — 5,410 live parts.
View Shower Spares