Nest 3rd generation - another, sorry!

[Rick C]

I wonder if anyone would have time to look at my particular Nest installation query - any help would be hugely appreciated. I would class myself as a pretty good diy'er but I am worried that one slip could fry my boiler.

I have just purchased a 3rd generation Nest and need to install to the following set up:
• Vaillant ecoTech Plus 428 boiler
• Drayton LP522 Programmer (pic 1)
• Drayton wired room thermostat (pic 2)
• hot water tank in airing cupboard upstairs.

I don’t appear to have many wires to swap over to the Heat Link, but am not sure which wiring diagram to use from the Nest manual. I also can't see how the existing thermostat in the hallway links to the boiler (the supply to the thermostat also looks like it may be 230v - so I may have to use the usb power?). The thermostat is quite far away (2 rooms in between) from the existing boiler.

Drayton LP522 Programmer

• Rick C
• 2 Dec 2016

Drayton thermostat

• Rick C
• 2 Dec 2016

My wife and I would be very grateful of help with the wiring! many thanks in advance, Rick.

 

[AGAS]

try the sparkys forum

 

[jackthom]

Is there another wiring centre somewhere where everything connects together?

 

[OwainDIYer]

There should be a wiring centre.

You can follow the diagram in the Next manual for ocnnection to the programmer, it's just mains and call for heat / call for hot water.

Live - Nest L, 2 and 5 - L you will need to link L to 2 and 5 on the Nest.
Neutral - Nest N - N

Heating call for heat - Nest 3 - Progrmmer 4
Hotwater call for heat - Nest 6 - Programmer 3

That takes care of the Nest Heat Unit. You may have to link a couple of terminals in the thermostat. Usually 1 and 3, and disconnect 2 which is connected to neutral. This takes the accellerator heater out of circuit.

Do NOT connect the Nest Thermostat to these wires. You will have to power the Nest Thermiostat from the plug-in power supply.

 

[Rick C]

Thanks for the replies and help, much appreciated, I have a feeling the other wiring centre may be in the eaves behind a lot of crap we have put up there, will pull out and take a look - along with the crimbo decorations! cheers again