Thanks for your replies, and as I live in the property I don't need a land lord cert' thanks.
Had a rethink while sat on the loo and concluded the probs started when I fitted additional rad and towel rail, pushing sysytem over capacity (12 rads). Fitted external Expansion Vessel, new flow...
Baxi Bahama Lockout. Hi, reading through the forum it's seems I'm one of the unlucky one's that has this boiler. Like others I have replaced numerous flow swithces and had to change the expansion vessel. I have a small leak in the system but the pressure only drops .25 bar over two weeks.
I...