Thanks Dave. With that info. we have read the manual at some length and that tallies. But we're a little unsure how to flush out with a proprietary descalant and disconnect/reconnect the water pipes safely as it suggests.
May be we need to get a plumber in.
Thanks very much for the lead.
Heating system works fine as far as we can tell but hot water runs hot and cold with eventual automatic switch off showing code 2 as the fault. Code 2 is 'overheat'. Have reset but reverts to same problem each time. Can anyone offer a view as to the cause please?
