UK trade guideBoiler Spares 5 min readUpdated 11 July 2026

How to Replace the Flow Sensor on a Vokera Vision 30C (UK)

Step-by-step UK guide to replacing the DHW turbine / flow sensor on a Vokera Vision 30C. Part numbers, torques, commissioning.

Vokera

The part

Swap the DHW turbine on Vokera Vision 30C when hot water runs cold at low flow or the boiler fails to fire on demand.

Isolate safely

Isolate cold mains at the boiler's blue isolator. The sensor on Vokera Vision 30C clips into the hydraulic block with two retaining clips.

Fit and commission

Fit new O-rings and align the turbine so the flow arrow matches the cold mains direction.

Recommission checklist

Refill the Vokera Vision 30C to 1.2 bar cold. Bleed high-point radiators and the internal AAV.

Run a full flue-gas analysis after 15 minutes. Log the reading against the OEM commissioning envelope in the Benchmark book.

Frequently asked questions

Can I clean rather than replace?
Yes for a limescaled unit — soak the turbine in citric acid, but replace if the Hall-effect PCB is corroded.
What minimum flow triggers?
The Vokera Vision 30C typically ignites at 2.5 L/min. Below that, check the aerator on the DHW outlet.
Do I need to notify the manufacturer?
Only if the Vokera Vision 30C is in warranty — Vokera require log of any part swap for labour claims.
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