Thanks very much for the response, I think pressurising it will be the eventual outcome as she wants a decent shower too and has talked about a shower pump.
For now though to get her up and running I’m going to try the magnet option as...
So...
My mother moved into her new home a few months ago , house about 20 years old. The central heating is open vented.
Her heating had an issue where the rads would come on when only calling for hot water.
So Friday I changed her 3...