My Britony Combi 80 central heating system has stopped working (but hot water was OK) and the pressure gauge shows zero. After bleeding the radiators, hot water also failed. The operating manual is next to useless and seems only concerned with installation rather than operation. I've looked through previous posts which refer to flexi-hoses and knobs, but can't find anything that adjusts the pressure gauge. Can anyone help?

kingman.mp4, November 2007

Under the boiler on the pipework there should be a valve
with a small lever on(known as a lever valve) fitted too the
cold water supply into the boiler,also on the central heating return pipe there should be a non return valve,between these two fittings a 1/2" braided hose is fitted to facilitate filling of the central heating system,this is done by fitting the braided hose and by opening the lever valve water will be passed from the cold mains water into the central heating.stop filling and re-vent the heating system when the pressure guage reaches approx 1.1/2 bar.after venting check the pressure and top up too approx 1.1/2bar.

tim, December 2007