It's summer so I'm not using the central heating but the pressure on my boiler keeps dropping. I have to top it up once a week.
I have a combi boiler Vaillant hrpro-144393. where would the leak likely be?
Problem could be in a leaking pipe within a system, valves or inside a boiler ( faulty heat exchanger) not enough pressure in a vessel or PRV .
You need gas safe reg engineer to service your boiler