A04
Vokera fault code
Vokera A04: insufficient system water pressure
You can usually fix this
The water pressure in the heating system is too low for the boiler to run. Vokera says to check and refill the system pressure, then reset.
Recommended pressure when cold for Vokera boilers: 1.0 to 1.5 bar.
What you can safely do
- Let the boiler cool and read the pressure gauge.
- Refill through the filling loop until the gauge reads between 1 and 1.5 bar, as Vokera recommends for a cool system.
- Reset the boiler and check it runs normally.
Call a Gas Safe engineer if
- The pressure keeps dropping.
- You can see water leaking.
Find a Gas Safe engineer near you
Opens the official Gas Safe Register search.
Applies to: Vision and Compact A. Codes can differ between models, so check your manual.