Connect 18 year old Daaldrop with 2 wire to Nest 3rd gen

[GuustFlater]

We bought a house with this Daaldrop central heating system. It has one of these overly complicated thermostats in the living room what is connected with 4 wires (we have 6 available!).

I realized that this question has been asked before but the descriptions are puzzling me. Perhaps this picture of the board wil help.

https://i.postimg.cc/9XSdckS0/temp-Imagecz-Wkuu.avif 

[Patrick_Caezza]

@GuustFlater 

What type of system is that control? HVAC, Boiler?

Does your Nest also have a Heat Link?

[GuustFlater]

@Patrick_Caezza

Boiler (central heating and warm water combined)

It's the 3rd gen Nest so it comes with a 2nd unit that needs to be installed at the heater. I assume that that is a "heat link" ?

[Patrick_Caezza]

@GuustFlater 

You are correct.

Unfortunately, I know nothing about the Heat Link and can't be of any help.

[tajennifer]

Hi GuustFlater,

Thanks for posting. I understand that you want to install a Nest Learning Thermostat in your four-wire system. For a correct and safe installation, I recommend contacting a Nest Pro or technician. 
Please let me know if you have more questions.

Best regards,
Jenny