How Can I Verify My Landis & Gyr RWB2 Programmer Is Faulty?

Hi,

I suspect my Landis & Gyr RWB2 Programmer to be faulty as my HW is working fine but I have no CH. I have tested the room thermostat, pump and 3 way valve which are all working fine.

Does anyone know which contacts I can short on the backplate to bypass the programmer and see if the CH fires up to confirm if it is the programmer at fault?

Thanks