I have the same issue
Heating fires upt he boiler and I have hot water downstairs.
But hot water up stairs is very marginal
I'm sure the boiler must have a water pressure switch that fires it up when the tap is running. Maybe the switch is broken.
I think my switch is marginal operation and I'm trying to get a user manual to find out how to locate and mend it
Cheers
James
James, December 2007
