Hi roger,

I'm not sure where most of those figures came from - they sound like garbage
to me!

I got the figures from the boiler manual, but I have no idea what they
mean!

Please explain what you mean by "I checked the pressure on the expansion
vessel".

I checked the pressure using a standard car pump with a pressure gauge
attached to the valve on the expansion vessel. This showed 2.25 bar
which seems high so I reduce it to 1 bar but this doesn't resolve the
problem.

I have an engineer coming tomorrow and will find out what he thinks the
problem is and how he plans to fix it.

Paul.