worcester greenstar 30si
GCN 47-311-85
blue light fast flash
[lockout reset light not lit?]
installation manual
page 58
volatile lockout
the next step would be to check
is the pump spinning? can normally hear/feel it YES/NO
is the fan spinning? YES/NO
checking the fan is going to be difficult without taking boiler casing off [very tricky to refit]
if fan is not spinning would have to test power to fan
manwithnoname
May 2012