New boiler misbehaving

moneysavingplumber

Pump valves leaking onto MV are always a favourite, usually only takes out the motor on the valve though, not had one knock out the 3A fuse myself before. See if the installer will call in Worcester, that way he can answer all the technical info and it's then down to him if the call does become chargeable (usually manufacturers use discretion in these situations and don't always charge anyway, it's only when it's an obvious fault on installation that no-one's checked usually).