Nest thermostat on a glowworm flexicom 18sx

[Robbie1182]

I currently have a glowworm flexicom 18sx boiler with no thermostat or controls and I want to be able to set my heating to come on during the night! I was thinking of the nest but unsure if it can be used on my boiler type?! If it can does anyone have a wiring diagram for this please?? Thanks in advance.

 

[ianmcd]

yes it can , there are hundreds of posts on here telling you how to do it

 

[CBW]

Your boiler manual will show you an electrical diagram, and the Nest will also have wiring diagrams for different setups. As @ianmcd has pointed out there’s literally hundreds of posts on here (usually at least 1 a week). Just use the search function in the top right hand side.

 

[Robbie1182]

Thanks The Novice, only new on here so appreciate the direction.

 

[stem]

I assume you are referring to a Nest Gen 3 with a separate Heat link and thermostat. If so, the Nest Heat link terminals 2 & 3 are connected to the two Gloworm Flexicom boiler terminals shown here. [24v and 0v] as you don't have an existing thermostat there will be a link inserted between the two terminals that should be removed first.

Then the Heat link also requires a 230v mains supply to N L & E which connects into these terminals here along with the wires presently in place.

The Nest thermostat can be powered by connecting it to the Heat link terminals T1 & T2 which are provided for this purpose or via a separate plug in power supply.

If you have to open up a room sealed part of your boiler to access these terminals (I don't think so, but I can't remember for sure if it does or not) then it's not a DIY job and should be done by an RGI (Gas Safe) engineer who can perform the necessary tests to make sure that it's sealed up again properly afterwards.

If you are considering a UK version of the e-Nest which is battery powered and doesn't need a mains supply, then these terminals [24v and 0v] simply go to the e-Nest 'C' and 'NO' terminals

 

[Robbie1182]

Thanks for the detailed info stem