My boiler seemed to working fine until I noticed the pressure dropping. I have since realized that there is no water getting into my boiler. The boiler is the ocean alpha 240 eco.
Find the filling loop and open the valves on it to refill to just above 1-00 Bar, unfortunately the loop could be anywhere, but usually in a cupboard near to the boiler it can be recognised as a short piesce of silver braided flexible hose between two chrome valves