I have a ferroli optima 700 combi boiler. I get hot water while the heating is on, but only get intermittant hot water when heating is off. Any advise could help and if it is a faulty component how easily could I fix/replace it? Thanks in advance

David, November 2007

maybe in need of service if the boiler isnt kicking in when hot tap is turned on, have you got decent pressure on hot tap?

Ian, December 2007

Sounds like a split diaphragm in the DHW housing assembly,Cost about£6 /£7 to replace yourself.
Quite an easy job consult your boiler troubleshooter, turn off electric supply ,isolate flow valves turn off cold water and drain boiler . you are now ready to work on the boiler. Put back in reverse!

Tim Hutton, November 2007