https://www.googlenestcommunity.com/t5/Nest-Thermostats/Neat-heatlink-wiring/m-p/244761#M49214 <P>I assume you are talking about the cores at the old thermostat end, is that correct?</P><P>Red = Live</P><P>Blue = Neutral</P><P>Yellow = Switch Wire to your pump</P><P>Having said that, those are the normal connections at 99% of thermostats.</P><P>Your booklet with the Nest shows clearly the connections you require, but you need to know what system you have before your start. ie: System Boiler, Combi Boiler, Y Plan, S Plan etc., etc.</P> Fri, 23 Sep 2022 19:22:22 GMT Frustratedddd 2022-09-23T19:22:22Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/Neat-heatlink-wiring/m-p/244022#M49067 <P>Hi, I have a Potterton thermostate which I am trying to replace with the best heatlink.&nbsp;<BR />I have three wires, Blue, red and yellow. Could anyone shed some light as to what connections these should be wired to on the heatlink. I’ve isolated the red, blue as Common and cannot turn the heating on.&nbsp;</P> Thu, 22 Sep 2022 11:50:05 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/Neat-heatlink-wiring/m-p/244022#M49067 Matt15 2022-09-22T11:50:05Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/Neat-heatlink-wiring/m-p/244761#M49214 <P>I assume you are talking about the cores at the old thermostat end, is that correct?</P><P>Red = Live</P><P>Blue = Neutral</P><P>Yellow = Switch Wire to your pump</P><P>Having said that, those are the normal connections at 99% of thermostats.</P><P>Your booklet with the Nest shows clearly the connections you require, but you need to know what system you have before your start. ie: System Boiler, Combi Boiler, Y Plan, S Plan etc., etc.</P> Fri, 23 Sep 2022 19:22:22 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/Neat-heatlink-wiring/m-p/244761#M49214 Frustratedddd 2022-09-23T19:22:22Z