How to Replace the Auto Air Vent on a Vokera Vision 25C (UK)
Step-by-step UK guide to replacing the brass automatic air vent on a Vokera Vision 25C. Part numbers, torques, commissioning.
Vokera
The part
Fit a new AAV on Vokera Vision 25C when the boiler airlocks on start-up or the pump makes gurgling noises after refilling.
Isolate safely
Isolate flow and return, unscrew the AAV from the top of the pump head or air separator on Vokera Vision 25C.
Fit and commission
Loosen the AAV cap one full turn once refitted — a fully-closed cap defeats the float.
Recommission checklist
Refill the Vokera Vision 25C 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
- Any special height?
- Fit the highest point of the Vokera Vision 25C circuit — that is where entrained air collects.
- How often should I service?
- Annually — the float sticks with sludge in unfiltered systems.
- Do I need to notify the manufacturer?
- Only if the Vokera Vision 25C is in warranty — Vokera require log of any part swap for labour claims.
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