DCH fine, but I can only get a steady flow of hot water with the tap fully open, and although hot, its certainly not 90'C as in Spec sheet, and if I turn any cold top on fully at the same time I lose the hot water. Any ideas out there? Thanks.

Splashback, January 2013

90'C? That would be a very dangerous boiler.

The boiler raises the cold water through a temperature rise at a given flow rate. From memory a vcw 242 raises the water through 35'C at a flow rate of approximately 9.5 litres/minute.

As for the water stopping, that would probably be a mains pressure is rather than being boiler related.

Carefree, January 2013