nest thermostat

Hi All - new to the forum and would appreciate some expert guidance I would like to install a Nest to control the boiler. the old thermostat used 2 wire (R & W), which are connected to CN10 on the NHB board. I have added a blue and green wire to provide power to the thermostat but don't know...

...or maybe it isn't? Here's the wiring setup of the thermostat I just removed. Keep in mind I cannot confirm if it was ever wired correctly to begin with but the old thermostat chewed through 3 x AA batteries very quickly. Here's the wiring of our new Nest thermostat: However, the Nest...

Hello all, I’m new to this forum and would like somebody to really help me. I had two Navien NCB 240 boilers installed three years ago, One boiler for my tenant upstairs and one boiler for the first floor and basement and I’ve attached the picture of a switching relay and my nest thermostat. It...

We recently replaced our some of our older thermostats and installed Nest thermostats on 3 of our 6 zones in the last month or so. (zone 6 is hot water) Everything was working great. The past week the 2 heating zones which do not have Nests installed aren't heating. The thermostats seem to be...