Another Nest wiring post - timer programmer and wireless thermostat

[wowcl]

Hi Guys,

Apologies for another 'How do I wire my Nest' post - but I think I'm in a fairly unique situation.

I currently have a Danfoss RX1 thermostat receiver wired into my boiler. I then have a Danfoss TS715SI timer programmer wired into that.

I'm guessing I would be just pulling out the timer/programmer altogether, and then replacing the wireless receiving with the Heat Link. Removing the timer would mean only 4 cores come from the boiler: Live, Neutral, Earth, Call for heat switch(?)

Both wires have a grey core that has been trimmed.

I suspect it will be wired up like the third image - but not totally convinced by the bridge!

Thanks for you help!

 

[stem]

If the wires at the other end are as you describe, with brown and blue being the 230v mains supply and black being the switched live, then picture 3 is correct, including the link between L and 2. That provides a live supply to the switch, which is then applied to 3 when the Heat link switches the heating on.

You need to be sure the connections are as you suspect though. Some boilers use 24v for their control and putting 230v on it is never a good idea. From what I can see this doesn't appear to be the case here, but best to check.

I would also put the Nest earth wire in the earth terminal to keep it safely out of the way. However Nest say that an earth connection is only required if you are going to wire terminals T1 & T2 to the Nest thermostat.

 

[wowcl]

If the wires at the other end are as you describe, with brown and blue being the 230v mains supply and black being the switched live, then picture 3 is correct, including the link between L and 2. That provides a live supply to the switch, which is then applied to 3 when the Heat link switches the heating on.

You need to be sure the connections are as you suspect though. Some boilers use 24v for their control and putting 230v on it is never a good idea. From what I can see this doesn't appear to be the case here, but best to check.

I would also put the Nest earth wire in the earth terminal to keep it safely out of the way. However Nest say that an earth connection is only required if you are going to wire terminals T1 & T2 to the Nest thermostat.

Thanks a lot! Wasn't sure if the live for switching would've just been pulled from the Live terminal, so thanks for clearing that up.
Will double check the wiring, but pretty sure it is 230v!