With the expansion diaphragm split and in need of replaceing, how much should i expect to pay for replacement. and is it standard pratice to just add on an external expansion vessel instead of removing the boiler to replace the original.?

royal, November 2010

Generic vessels are in general, cheaper than manufacturers specific vessels.

There is no hard and fast rule on replacing or renewing, if you fit a new vessel rather than replacement, ensure it has the capcity to deal with the system requirement (10 ltrs should be good for a standard type system).

Price? Retail and trade would be very different, look around on the net for a guidance.

Carefree, November 2010