E02: Condensate comes from the burner/flue area. Could a leaking heat exchanger (or closely associated pipework) also put water into the burner area?
A77: Could the condensate drain now be blocked with crud?
More stuff:
http://www.diynot.com/diy/threads/repressurised-pv-on-ariston-boiler-no-heating-or-water.350215/
And one oddball cause
http://fixfault.com/answers.php?id=1741
XXX
February 2016