Sfx - that must be so infuraiting. We had problem with boiler in last house, it was the 3rd co. who we called that finally figured out problem. Seems to me boilers are quite technical and each make has it's own nuances, not all plumbers have indepth knowledge of all boiler makes. Can you call boiler co. direct and ask for help?
Nice to see some of you at Sat night, it was good fun 
Tilly - thanks for offering to host, may have to play it by ear tom, Ds2 having some shocking nights and is massively overtired (as am I). Will see how tonight goes.
Been to Whitton gym today with 2 friends, we had the place too ourselves and all kids had a blast on the inflatables