What cable is required for Nest Heatlink?

[York23]

What cable do I need to connect a Nest HeatLink to my boiler (Ideal Mexico)? A description would be useful, a link to an actual sales site even better. Nest customer service seemingly are unable to answer this question. Although they provide instructions in diagrammatic form for DIY installation, any question on installation and they can only advise to get it professionally installed. It's as if they do not understand their own product.
Question originally posted on ElectriansForums...replies advised I post here instead. Thank you.

 

[ShaunCorbs]

Every system is different that’s why they just say get a pro out

Remove your existing two channel programer and there should be a wiring diagram on the back of your programer match this up with the new drawing eg nest book

 

[king of pipes]

0.75 flex is on mine but seen Bell wire used right or wrongly ? Ko

 

[York23]

Every system is different that’s why they just say get a pro out

Remove your existing two channel programer and there should be a wiring diagram on the back of your programer match this up with the new drawing eg nest book

Thank you but the question was one about cable to connect the HeatLink to the Boiler. The HeatLink will be in a different room to the old CH Controller,
[automerge]1575222273[/automerge]

0.75 flex is on mine but seen Bell wire used right or wrongly ? Ko

Thank you but image shows the thermostat not the HeatLink.

 

[ShaunCorbs]

Thank you but the question was one about cable to connect the HeatLink to the Boiler. The HeatLink will be in a different room to the old CH Controller,
[automerge]1575222273[/automerge]

Thank you but image shows the thermostat not the HeatLink.

What boiler do you have ?

 

[king of pipes]

0.75 flex is on mine but seen Bell wire used right or wrongly ? Ko

Thank you but the question was one about cable to connect the HeatLink to the Boiler. The HeatLink will be in a different room to the old CH Controller,
[automerge]1575222273[/automerge]

Thank you but image shows the thermostat not the HeatLink.

Ok I will try harder 0.75 from the boiler open therm connections to the heat link which is in the cupboard directly behind the stat, picked a power supply up from there and connected the heat link and then the stat any clearer ?

 

[York23]

Ok I will try harder 0.75 from the boiler open therm connections to the heat link which is in the cupboard directly behind the stat, picked a power supply up from there and connected the heat link and then the stat any clearer ?

Thank you. Two separate cables then ?

 

[Ziggie]

Nest documents that the fuse is a 3 amp one - so anything using more than 3 amps will cause the fuse to blow.

0.75mm allows for 6 amps.

 

[York23]

Thank you. After further research I decided on the Wiser unit which is now instaleld and working just fine.

 

[Aquarius]

Nest documents that the fuse is a 3 amp one - so anything using more than 3 amps will cause the fuse to blow.

0.75mm allows for 6 amps.

So 0.75mm is not permitted if it allows for 6 amps?