wiring waterline under floor heating to 8000 style Worcester boiler

[Zehroni]

I am trying to wire my under floor heating wiring centre back to the boiler so that it can fire when there is a demand for heating. And this is how the system is set up.

the room thermostat and programmer (one in each room/ one zone) has three wires, N, L and L1 (live switch), these wires terminate at the designated zone donated by R in the wiring center diagram. therefore, it is powered by the wiring centre and when there is a demand for heating the L1 becomes live. consequently, the wiring center will open the actuator valve, starts the under floor heating pump and open the 2 port zone valve. And when the zone valve is open , the orang wire (connected to the "NO" terminal in the wiring center) becomes live (which I believe acts as live switch for the boiler. however, the boiler block connection in the wiring centre has 2 connections "COM" and "NO", my question is

how many wires I need to connect from the wiring center to the boiler? I believe I need single wire of any colour that will be connected to the "NO" at the wiring centre and to the "LR" at the boiler.
if my believe is right , why the wiring center shows 2 connections to the boiler the "COM" and "NO". the "COM" is the permanent live to the zone valve and should not be connected back to the boiler.

 

[ericmark]

In the main we try to use same supply for all central heating parts, some items like TRV heads use to AA batteries so clearly they can't use same supply, but with 230 volt we aim to have one switch to turn off all. But some boilers use 24 volt for control, some 230 volt and some zero to 48 volt, so the underfloor heating has to be arranged so as many systems as possible can connect to it so best compromise is to have volt free contacts.

G1 it says is volt free. The boiler also gives a connection diagram

it continues

You have not got option to use BUS, so 230 volt out to AC power and LR to G1 NO and link wire N to Com plus the earth wire of course, so 4 core boiler to wiring centre.

Maybe I have found the wrong instructions used this for underfloor and downloaded boiler instructions here you can verify I got it right or wrong?

 

[Zehroni]

[QUOTE="Maybe I have found the wrong instructions used this for underfloor and downloaded boiler instructions here you can verify I got it right or wrong?[/QUOTE]
many thanks, you are spot on, this is the right instruction.
just to confirm my understanding and if we say the boiler is the starting point so that everything is controlled from the same point. I need 4 core cable and the cores will be connected as follows at the boiler end;

brown to the L of the "230v out" block in the boiler
blue to the N of the "230v out" block in the boiler
yellow/green to the earth in the boiler
black to the LR of the boiler

And at the wiring centre, the above wires will terminate as follows;

brown to the L of the "AC" block in the wiring center
blue to the N of the ""AC" block out" in the wiring center
yellow/green to the earth on the PE in the wiring center
black to the NO of the "G1" block in the wiring center

correct?