Had a leak which originated from auto air vent. Wall fuse blown because water dripped down onto control panel and board. Engineer came at callout cost £78 and identified auto air vent at fault. Would have to ask manager how to replace. Never came back. Took panels aout and dried, fitted back, installed fuse, OK.
Still need to change auto vent. How difficult, how long ?

James T, October 2012

AAV located at rear of heat exchanger behind flue turret manifold
very difficult to access
would need to remove FAN & burner plate to gain access
possible for experienced gas engineer to remove & fit AAV in 30 minutes [provided AAV hasnt seized onto HEX housing]

seems a bit extortionate to charge someone £78 & not repair/fix the boiler

Q, October 2012