Help with worcester greenstar 24 ri

[Hobo128]

Replaced a baxi solo with a worcester greenstar 24 ri today and upgraded the programmer and the room thermostat with drayton controls. The system is a y plan, when I put on hot water the pump runs and boiler fires, 2 way valve stays in hot water position. When I put hog water on the pump runs and 2 port moves over to heating but boiler stops firing up. Pup continues to run but no ignition.
Please can anyone shed some light .

 

[Last Plumber]

Need to check wiring regarding valve.

Is the pump wired on a pump overrun from boiler ?
Or is it wired separate from a wiring box.

Check SL from valve to Boiler Also if no SL check PL to microswitch.