Nest Thermostat and Baxi Combi 105E

[kedzis]

Has anyone wired Nest Heat Link with Baxi boiler?

Baxi Combi 105E thermostat wiring

• kedzis
• 28 Oct 2014
• 2

When i look at my combi boiler connections and Nest manual the most appropriate would be to to connect LOW Voltage Option not as Switched Live in Nest manual.

Untitled

• kedzis
• 28 Oct 2014
• 2

What would you recommend?

 

[jackthom]

already replied to other thread but here it is again.

Yes use the nest as in the LOW voltage diagram even though it will actually be switching live to the switched live wire.

Are you removing the external timeswitch (if there actually is one) and connectiing the heatlink directly to boiler terminals 1 & 2 ?

 

[kedzis]

Thank you, sorry for double post. Do you think using Low voltage option for 230V SL is safe to do? I do not want to burn the main board. I am going to remove the yellow link between terminal 1and 2 on the boiler and to connect it to 2 and 3 on Nest and connect Live and Neutral from the boiler to the Nest directly. I have Baxi manual round timer on the boiler which I am going to leave permanently on. I believe it should work. Would you agree?

 

[Dan Robinson]

Don't confuse Low voltage for volt free.


Only need one thread.

 

[jackthom]

I see, so there was no room thermostat previously and you are removing the wire link between 1 & 2.

That sounds OK and don't worry about damaging the heatlink contacts because in fact the same internal switch is used regardless of whether it is in mains or low voltage operation.

 

[kedzis]

I see, so there was no room thermostat previously and you are removing the wire link between 1 & 2.

That sounds OK and don't worry about damaging the heatlink contacts because in fact the same internal switch is used regardless of whether it is in mains or low voltage operation.

Yes, there was no thermostat installed to this boiler, but i have old thermostat left after previous boiler which wires i may use to run 12V from heat link to the new thermostat.

 

[kedzis]

Don't confuse Low voltage for volt free.


Only need one thread.

Thanks, i think i confused low voltage and volt free. I am going to carry on this thread only

 

[Dean744PiN5]

Connect 1 and 2 on boiler to 2 and 3 on heat link, polarity is not important.
Live and neutral from boiler to live and neutral in heat link.
If using existing wires to power the nest thermostat itself, make sure they are not connected to anything and run a continuity test by joining the 2 wires at one end and testing for continuity at the other end.

 

[kedzis]

Shall i wire L and N on the boiler before the 2A fuse on after?, looking at the picture of the terminal on right hand side or left? Does the heat link have any fuses? Looking at the Nest manual i also see that T1 on the Nest should be connected to Earth? Can i connect it to the Earth Terminal on the boiler?

 

[Dean744PiN5]

Heat link doesn't have fuses, take L and N from supply side to boiler, T1 DOES not require an earth.
Take my advice I have fitted over 20 of these units.

 

[Agile]

Ked, could you briefly tell us what you are hoping to achieve by using the Nest?

Tony

 

[kedzis]

I just need a learning thermostat and I like Nest's design

 

[kedzis]

Ked, could you briefly tell us what you are hoping to achieve by using the Nest?

Tony

why are you asking? do you have any better recommendations?

 

[dj_chrispy041981]

Hi I have just purchased a nest thermostat and looking to install it with my baxi boiler. Can I confirm that I need to Connect 1 and 2 on boiler to 2 and 3 on heat link and Live and neutral from boiler to live and neutral in heat link. Do I need to remove the link on 1 and 2 on the boiler. One last thing, what gauge cable should I use? Many thanks in advance.

 

[DP]

H/N 4