I have a Nest stat, heatlink mounted and has a 4 way & earth connected with a separate 2 way connected.
2 way to go to wall stat T1 & T2 12v from the heatlink.
Earth to earth
Heatlink L to L on boiler
Heatlink N to N on boiler
Question is 2 & 3 on heatlink ( i think are supposed to...