Installing Nest 3

[Deepu Thomas]

Can anyone advise on the right way to replace the danfoss tp9000 thermostat and ts2 sensor with the nest. I have attached pictures showing the current setup.

Thanks in advance,

 

[OwainDIYer]

Function - Nest HeatLink - Danfoss

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 - Danfoss 4
Hotwater call for heat - Nest 6 - Danfoss 3

Danfoss 5 and 6 - disconnect. These are the connections to the Danfoss remote sensor. You can connect these wires to Nest T1 and T2 on the HeatLink and on the Nest Thermostat, if you are connecting the Nest thermostat in place of the Danfoss remote sensor.

https://www.howson.me/content/images/2016/07/gascontrol/installer-guide.pdf
https://s3.amazonaws.com/support-as...Nest-Learning-Thermostat-Install-Guide-UK.pdf

 

[law1213]

Hi -

I have the same Danfoss unit and a similar setup (but with 3 wires in Neutral and 3 in Live). With these additional wires I gather it might be difficult getting them into the Nest HeatLink (small holes).

Was wondering if I'd be ok using something like these connectors (http://www.screwfix.com/p/4-way-push-wire-connector-773-series-pack-of-100/27374)?

Or For L - Live, would I be ok putting one of each of the live wires from L on the Danfoss into L, 2, and 5 on the Nest HeatLink (as I will be linking L, 2 and 5 anyway? So only two wires in each slot)?

(See pics attached).

 

[OwainDIYer]

You've already got a lot going on there. I think I'd take the whole lot out and put in a small wiring centre box, with link wires as appropriate, then take cable out to the Next box adjacent.

 

[law1213]

All wired in, but noticed no hot water option? Now it is a 3rd gen Nest and I did include the call for hot water (Nest 6) cable. Should I have a hot water option (on/off)?

 

[law1213]

It occurred to me that maybe my link cable from pins 2 to 5 may not be making contact (seems to be secure however), if I'm supposed to have a hot water option, I'll double check the pins tomorrow morning. I do seem to have hot water but it could've just been kept hot in the tank.

 

[law1213]

Managed to resolve this.

FIX: Go into professional settings change boiler type from combi to system boiler. Hot water option then appears and works.