hi guys,
I've removed a internal oil boiler that has a fused spur pump and a fused spur power to boiler.
If it's not striaght forward I'll get a sparky. But if it is I'll do it with the help of you guys.
You need one cable for power to boiler and pump because both will operate together.
Also as new boiler is external it needs power for frost stat. Extra live wire (permanent live, but obviously from fused source from supply in house).
Grant external boiler has this built in and the manual will have the details of boiler wiring.
Rest of wiring - zone valves, etc, will be another issue