Hi,
Anyone advise if I need to drain the central heating to install a primary flow switch service kit on an Ace High?
From what I can see, it looks like I could just drain a few litres off the CH, as the boiler is the highest point in the system?
I did the DHW diaphragm last year and the manual was nice and clear, but there is nothing about the primary flow switch in there :(
Symptoms are PFS pin sticking, so I believe the service kit is the correct approach. The old one is probably full of scale.
TIA Someone