I have recently had installed by a qualified electrician the components of a Danfoss control pack with the wiring box. My problem is with the HS 3 port valve, the plumbing bit I did myself - it does not open the valve for the heating. Hot water is ok. The supplier said the thought it was the valve and supplied a new one - same problem. Looking at the actuator when not connected to the valve showed that the spindle was not moving sufficiently. Back to the suppliers for new actuator! Same problem. The electrian has double checked all the wiring and has confirmed the correct voltage from the room stat, and we have tried a new room stat.