I have my NEST working okay after installing myself with some expert help from these forums but as a glutton for punishment I have decided to re-locate the Heatlink to the airing cupboard upstairs (its next to the boiler in the kitchen at the moment). The problem is that when I wired the heatlink there were 2 connections to the live terminal on the old block, one obviously was the live feed for the programmer itself and the other one I did not worry about at the time just linking it straight to live again. The problem is if I re-locate then now I do need to work out what that feed is for so that I can re-connect at the wiring center upstairs (assuming it terminates there). Any idea what this would be for? It is part of the same 4 core cable that carries all the other Heatlink connections bar the HW satisfied which is separate cable. Thanks in advance...
Re-siting NEST
- Thread starter JC-DIYman
- Start date
It can be difficult to work out. The method of installation would have been chosen by the original installer, depending on where the various parts of your heating system are positioned in your home and the easiest way for him to run the cables and make the connections. So, no two installations are the same. Tracing the wire will be the only way to be sure.
Much will depend upon where the main live supply from the Fused Connection Unit (FCU) is introduced into the wiring. Some installers wire it to the boiler first, and distribute it from there. Others take it to the programmer first, and yet others to the wiring centre. I suspect that your unknown wire may will be a permanent live supply to the boiler.
You say that "It is part of the same 4 core cable that carries all the other Heatlink connections bar the HW satisfied which is separate cable." That means that the wire from the Heatlink terminal (3) heating 'call for heat' will be included in this cable. At the wiring centre the wire from Heatlink (3) will be electrically connected to the motorised valve's white wire. That should allow you to identify the '4 core cable' and then it's a matter of seeing what the unknown live wire in the same cable goes to. A test with a multimeter would then allow confirmation.
Much will depend upon where the main live supply from the Fused Connection Unit (FCU) is introduced into the wiring. Some installers wire it to the boiler first, and distribute it from there. Others take it to the programmer first, and yet others to the wiring centre. I suspect that your unknown wire may will be a permanent live supply to the boiler.
You say that "It is part of the same 4 core cable that carries all the other Heatlink connections bar the HW satisfied which is separate cable." That means that the wire from the Heatlink terminal (3) heating 'call for heat' will be included in this cable. At the wiring centre the wire from Heatlink (3) will be electrically connected to the motorised valve's white wire. That should allow you to identify the '4 core cable' and then it's a matter of seeing what the unknown live wire in the same cable goes to. A test with a multimeter would then allow confirmation.