How to Replace a Shower Flow Switch (UK)
Diagnose and fit a new flow switch on Mira, Triton and Bristan electric showers. Cures 'no heat, water flows' fault.
MiraTritonBristan
Function
The flow switch enables the heating element only when water flows. Stuck closed = element never energises.
OEM part numbers
- Mira Sport — 415.19.
- Triton T80 — P22310003.
- Bristan Glee — 5450014.
Fit
Isolate. Undo 4 cover screws. Unclip flow switch harness. Fit new switch aligned with the arrow marking direction of flow.
Frequently asked questions
- Why does the shower run cold after fitting a new element?
- Almost always flow switch failed at the same time — fit both together on units >5 years old.
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