Hi I have a pro combi85 he but when turning heating or water on all fans etc work but it does not fire up why is this

Orlando, February 2016

The fan is the first thing to happen - several other things need to happen (be satisfied) before the boiler lights up. It's very likely that it will need the skills of a specialist to determine what the problem is.

Fan - Pressure Switch (case) - Control electronics - Gas Valve - Ignition - - Any of these may be failing.

Good Luck..., February 2016