Nest Thermostat Heat Link Wireing advice

[davesparks]

So am I right in thinking it should just be a straight swap over for programmer to the nest heat link?

It’s not a straight forward swap because you won’t get those cables to fit in to the heatlink neatly and connect them in a safe and compliant manner. There certainly isn’t space inside the heatlink for the additional connectors you will need.

Why risk damaging a £200+ thermostat for the sake of £60 to have a professional install it? Plus a professional installer will fully demonstrate the operation of the system including features which may not be apparent just from having a go yourself.

 

[Nigel]

The Nest wiring diagrams are very straight forward.

If you cannot understand them then that answers your question on competency.