Protecting a boiler with a relay

[UKMeterman]

The other important question is can we have a photo of the rating plate of the pump. It may need special proteciton.

 

[Harry Palmer]

The other important question is can we have a photo of the rating plate of the pump. It may need special proteciton.

As requested:

link: sdr - https://ibb.co/iiZE5G

 

[Harry Palmer]

Basically, the cable that you would normally take from the boiler control to the pump goes instead to contacts A1 and A2. Brown in A1 and Blue in A2.
You then take power to the the other terminals on the contactor.
It’s preferable to take this power from the same source as supplies the boiler, but that may be impractical?
Connect Brown to terminal 1 and Blue to terminal 3.
From the bottom of the contactor you take power to the pump. Brown in terminal 2 and Blue in terminal 4.
I would then connect all the Earth wires together using a terminal block.

Also thank you too Spinlondon for taking the time and trouble to help

 

[Deleted member 26818]

Yes I wrote contacts A1 and A2 when I should have written terminals A1 and A2.

 

[Harry Palmer]

Get the wiring diagram for the boiler, identify the pump on the diagram for the boiler, connect A1 A2 where the pump is shown the on the wiring diagram for the boiler. Connect the rest as stated above

Update

To UKMeterman and spinlondon repectively, I have attched a basic wiring diagram below that I created in Microsoft Paint, can either of you please tell me if I have interperated your wiring guide incorporatiing the 'Contactor' switch correctly?

Thanks

Link: PROPOSED PUMP WIRING DIAGRAM - https://ibb.co/jUGgpb

 

[Deleted member 26818]

No.
You got from ‘Boiler to external pump connections’ to terminals A1 and A2 correct.
You got terminals 4 and 2 to external pump correct.
The power to terminals 1 and 3 has to come from another source (preferably the same source as supplies the boiler).

 

[Deleted member 26818]

I hope this explains:

Top FCU has whatever fuse is recommended for the boiler (3A?).
Lower FCU (13A?).

 

[Harry Palmer]

I hope this explains:
View attachment 39611
Top FCU has whatever fuse is recommended for the boiler (3A?).
Lower FCU (13A?).

I undertand where i went wrong, again thank you spinlondon for the wiring diagram and of course taking the much appreciated time to reply