WIRING FOR CENTRAL HETING/HOT WATER ??

[stevehayes]

i have a question: Y PLAN FULLY PUMPED system with 3-port mid position valve is wired up in a standard way i believe? BUT on diagrams the terminal box strips are numbered from 1-8! Does it matter what boxes are used, for eg on my diagram the orange wire from the mid position valve is connected in with the number 1 (demand) from the cylinder stat and live from both the pump and boiler! on my diagram it has these all connected to number 8 of the terminal strip. can these be installed as say number 5 of the terminal strip as long as they are ALL connected together?!! as on MY system they don't seem to be in number 8 but the system works fine. What I;m trying to work out is as long as all the wires link up together as per the diagram does it matter if they are in number order, eg 1-8??!

 

[AshaDPlumber]

No, the numbering is irelevant. As long as the wires are connected to what you have on the diagram. So all connections make and break in the right place.

 

[D_Hailsham]

Does it matter what boxes are used, for eg on my diagram the orange wire from the mid position valve is connected in with the number 1 (demand) from the cylinder stat and live from both the pump and boiler! on my diagram it has these all connected to number 8 of the terminal strip. can these be installed as say number 5 of the terminal strip as long as they are ALL connected together?!! as on MY system they don't seem to be in number 8 but the system works fine. What I;m trying to work out is as long as all the wires link up together as per the diagram does it matter if they are in number order, eg 1-8??!

The terminal numbers are not important. What is important is that the correct cables are connected together at each terminal. The terminals are independent of each other, just like in a terminal block from B & Q.

This is the wiring for a Y-Plan

 

[stevehayes]

thanks for your help, really appreciate it, understand now how it all works. learned a lot. i have a new cylinder stat to replace which i posted a post about a few days ago. haven't done it yet but want it done today. the wiring is c, 1 (for call) and 2 (for satisfied) as per instructions, and are the same for my previous stat. this is a daft question probably, BUT i obviously need to turn the power off before removing the wires and installing the new wires. The terminal box in my airing cupboard is linked to the mains obviously, BUT where would the fuse be for this? Is it connected directly to the main consumer unit/fuse box? There is not a separate fused spur nearby like with my immersion heater. Should I turn off the whole electrical supply to the entire house to be extra safe? I'm not gonna touch it until I am 100percent sure for obvious reasons.

 

[D_Hailsham]

The terminal box in my airing cupboard is linked to the mains obviously, BUT where would the fuse be for this? Is it connected directly to the main consumer unit/fuse box? There is not a separate fused spur nearby like with my immersion heater. Should I turn off the whole electrical supply to the entire house to be extra safe? I'm not gonna touch it until I am 100percent sure for obvious reasons.

Good practice says that there should be one switch controlling the electric supply to the heating system. If it's not in the airing cupboard, it may be near the boiler. If there is a wall switch near the boiler, turn this one off and check if your wiring centre is dead. If it is you should be safe to swap the thermostat.

Failing that, just turn off the power to the house. Then have fun resetting all the videos, clocks etc (just like GMT/BST)