boiler will not light with hw selected

[deanwillis]

hi , i have been having a few problems with my central heating / hot water
when i select h/w and c/h to on nothing happens , but when i de-select h/w the boiler fires up , tried changing tank stat but no joy , taken the actuator from the motorized v/v , it seems to be working , but i left it off and my h/w got hot , then c/h starts to get hot , do you think that it is the micro switch on the 3 way v/v and if so do i need to change the complete v/v :(

[marrtin]

Seems a logical conclusion to come to, but without comprehensive knowledge of how the installation is wired, it is difficult to be sure.

You can buy the motor separately, but not sure about the microswitch assy.