Nest Thermostat

[John Martin]

Hi There,

I have just purchased a new Nest thermostat in the hope that I could replace the existing Honeywell T6160. The existing setup is a Honeywell ST7100 controller in a Y-Plan layout.

Having looked at the circuit diagram for the old thermostat I cannot see that the new one will replace the exiting T6160 as the Nest diagram shows a SPDT switch which only gives me two wires to the controller, the existing thermostat has three wires, one common and two output wires with one connected via 270k resistor.

Is anyone familiar with the Nest controller wiring?

 

[muggles]

Simple job to replace your setup with a Nest. It would normally take me less than an hour, including drinking the tea. The T6160 needs to be removed, and one wire in the core of three should be isolated. The other two wire into the Nest backplate at one end, and the Nest Heat Link's T1 and T2 connections at the other end. You then need to run permanent live, neutral and switched live between the Heat Link and the wiring centre

 

[Alex123-4]

Hi Muggles,
Did you see my post about a NEST? I was asking about the Call for Heat (two wires on mine directly from Danfoss RMT 230 Thermostat)
When I measured across with my meter I read approx 100v dc.....Halstead Finest Platinum boiler - thermostat goes across L2 and L3 with short removed. No Programmer or zone valves. Appreciate advice. Thanks Alex23-4

 

[jackthom]

Just replied to that post.