Hi Robert,
I believe that is our very own SandyCam....
If you go to the member list, and to his public profile, you will find this contact.
sandy - kate (at) wargyll. fsnet .co.uk
He is certainly the boiler expert around here....I suspect he'll be along shortly.
Dave
Edit Jo: Modified the SandyCam's Email address to discourage search engines picking it up. If you want to use the Email remove the spaces and replace the (at) with @.