thescruff wrote on Feb 23rd, 2018, 10:35pm:Not going to answer the sparky question other than to say, the Boiler, Mv, Pump and room stat all have to be linked somewhere.
No, they don't in a situation like mine where there are two separate water systems and no, they're not clutching at straws.
Having converted to an unvented system everything is spot on. Just wish I'd bit the bullet earlier. Would have saved a lot of heartache and money and less hassle and a better system.