connect boiler and nest heatlink from the same switched fused spur

[FollowerOfTheRules]

My boiler is currently powered by a switched fused spur. The spur is located 40cm underneath the boiler.
I haven't checked but it is probably a 3A fuse.
My boiler is an Ideal Logic combi ESP1 35 : https://idealheating.com/uploads/documents/logic-combi-esp1-installation-and-servicing.pdf

I would like to add a Nest thermostat using the opentherm wiring as described here page 24: https://nest.com/support/images/mis...Nest-Learning-Thermostat-Install-Guide-UK.pdf

The wiring is relatively easy, I just need 230V AC N + L to power the device and then 2 low voltage wires to the Opentherm on the boiler.

My question is, where do I get the the 230V AC N + L from ? the easiest way and following the regulation.

Can I get it from the current switched fused spur that powers the boiler ?
if yes, shall I connect the nest heatlink N+L directly from the switched fused spur (load side)

or

shall I connect the nest heatlink N+L directly from the boiler on the MAIN input?


Thanks in advance.

 

[RandomGrinch]

Can I get it from the current switched fused spur that powers the boiler ?
if yes, shall I connect the nest heatlink N+L directly from the switched fused spur (load side)

Yes, the Load side.
...and if you are planning on powering the thermostat from the 12V supply from the Heatlink, you will also need an earth connection from the fused spur.

 

[muggles]

Worth noting that the front cover on this boiler forms the safety room seal, and as such should only be removed and refitted by a Gas Safe Registered engineer

 

[FollowerOfTheRules]

Thanks for tour reply. So it is allowed to have those 2 devices powered by the same switched fused spur from a electricity/building regulation perspective?

 

[RandomGrinch]

Thanks for tour reply. So it is allowed to have those 2 devices powered by the same switched fused spur from a electricity/building regulation perspective?

Yes, it could be considered a safer way of connecting the Nest.
Having a single point of isolation for both, could avoid incidents when a faulty appliance may inject mains into another that is otherwise isolated.

This is of course assuming that you can safely take another cable out of the FCU, using appropriate strain relief etc.

...and there's the issue that @muggles refers to.

 

[Ant1]

Can I get it from the current switched fused spur that powers the boiler ?

Yes, this is what is being shown in the Nest manual (I connected all my 3 Nest Thermostat to the spurs feeding the boiler)