Central heating OK.
D.H.W Intermittant working,ie,switch shower on and anything from 15/30 minutes will go to lock out.The triping times can vary.This boiler has given excellent
service over the years but has always been dogged
by this problem and never been completly cured
of "Locking out" on the D.H.W side.
Do your best ...
Ted.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.