Search results

  1. R

    Replace ST6400 controller w nest third gen heatlink

    Have now added schematic for Junction box
  2. R

    Replace ST6400 controller w nest third gen heatlink

    Well I tried to start and then realised that if I just remove thermostat wiring ( which carries 240v) from terminals 5 and 7 in junction box I then leave an open circuit for the heat valve ( see attached). Do I need to link terms 5 and 7 in junction box so that power could get to heat valve...
  3. R

    Replace ST6400 controller w nest third gen heatlink

    Johndmc. Thank the you.
  4. R

    Replace ST6400 controller w nest third gen heatlink

    hello I have an st 6400 honeywell controller on my heating system. Looking at the nest heatlink install guide I think I have an s plan system that also includes a pump. For the sr6400 present wiring includes live, neutral, red wire to terminal three (HW ON) and black wire to terminal four...
Back
Top