On 05/06/2019 14:29, John Rumm wrote:
snip

Most modernish Vaillant boilers have a very easy to get at expansion
vessel - typically on the right hand side of the case. Vis (silver thing
top right):

http://wiki.diyfaq.org.uk/index.php/...cotec824HE.png



It would be nice, but there isn't enough clearance above the boiler to
remove the Expansion vessel in situ - at least according to Vaillant anyway.

This one has the flat red vessel at the back, the one in the link does
look easier to change.