Bosch Greenstar floor mount combi P151 (kwb42-3) boiler pressure

pwoll

I have a Bosch Greenstar fs combi kwb42-3 boiler with a pressure gauge that is resting
less than 1 bar and need to top up the pressure to 1 bar. Need to know how to top up
the pressure. I cannot find and key or keyless valves in the unit.

EBEBRATT-Ed

1 bar is 15 psi so that is plenty.

Post a few pictures.

There must be a city water make up pipe feeding the boiler with a pressure reducing valve on it.

Unless you have antifreeze in the system?

pwoll

Ed
Yes there is a city water make up pipe feeding the boiler with a auto fill (green) valve on it. No other
valves after the auto fill valve. That the problem. See attached pics. Any ideas?

GW

Take a close up pic of that valve on your last picture. See what the numbers say on the tag

Anyway that’s the domestic water (or) plumbing, nothing to do with the 1 Bar dial