combi boiler

We’re soon to be moving to a rural property, I’m estimating a 70s build, it has Calor Gas supplied from an outside tank. The boiler is around 15 years old, possibly a bit older, the hot water is supplied by a large tank on a timer. As we might soon need to replace the boiler, what are the best...

In the attached photo, you can see a view of my boiler and plumbing system. I've been dealing with an issue of increasing pressure in my boiler for the past few weeks. Normally, when all the valves are in the down position, the pressure increases to around 0.5-0.75 bar every night. I manually...