We had a combi and some new radiators installed this year and I plan to replace a couple of the manual bleed valves with automatic valves.
I imagine that I will need to slightly top up the combi afterwards - which should be a straightforward process. The combi, a WB CDi comes with a plastic key which apparently fits in a valve on the underside of the boiler. Is it just a case of turning it on until the pressure gauge is indicating a pressure of around 1 bar and then turning it off?
-- rbel