UK trade guideShower Spares 4 min readUpdated 11 July 2026

How to Replace the Thermostatic Cartridge on a Methven Aurajet Aio Bar (UK)

UK guide to swapping the thermostatic cartridge in a Methven Aurajet Aio Bar shower valve. TMV2 compliance, part numbers, tools.

Methven

The part

Rebalance a scaling Methven Aurajet Aio Bar 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 Methven plastic housing.

Commission

Balance hot and cold to within 0.5 bar. Run the Methven Aurajet Aio Bar 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 Methven Aurajet Aio Bar cartridge is TMV2 approved out of the box. For TMV3 (healthcare) fit the -HC suffix variant.
OEM or aftermarket for Methven?
For TMV2/TMV3 compliance always fit genuine Methven cartridges. Aftermarket voids the Aurajet Aio Bar approval.
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