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Steam-Help with Thermostat wiring, New Yorker 2 wire

Nysteamer
Nysteamer Member Posts: 22
Hello Everyone,
Current setup
-New Yorker Boiler.
- T Stat something no longer made
looking to put in a Wifi Thermostat for remote functionality.
Only steam heat no AC.

I am certain this topic has been answered somewhere, however I have not been able to pinpoint some finer details reading through various discussions. I am trying to identify how I can add a C Wire to the current wiring scheme. Upon review of one of the manuals diagrams it appears there are two places the t stat wiring goes to which is blue and brown on each one. I don't know if it is possible to connect a third wire somewhere to be "C" or do I need to apply one of the methods noted throughout the web, which is adding an external transformer, add a wire etc for an Ecobee or nest t-stat.

Attached you will find the wiring diagram pulled from the manual.
Thanks in advance!

Comments

  • ratio
    ratio Member Posts: 3,623
    Blue from the boiler to R on the stat, brown to W, yellow to C.

    Be sure to configure your new stat correctly, esp WRT number of heating cycles per hour.

  • Nysteamer
    Nysteamer Member Posts: 22
    hello ratio!

    Thanks for the super fast response! I will get on this. One question in regards to the current transformer. Is the 40va enough? or would it be a problem in terms of the connected loads. Draft vent, pressuretrol, lwco etc? I've come to read that these t stats draw a bit of power
  • ratio
    ratio Member Posts: 3,623
    Hard to tell without knowing the current load & the load of the new stat, but if it's undersized it'll just blow the fuse/CB. Try it & see is the cheapest solution.
  • Jamie Hall
    Jamie Hall Member Posts: 23,270
    ratio said:

    Hard to tell without knowing the current load & the load of the new stat, but if it's undersized it'll just blow the fuse/CB. Try it & see is the cheapest solution.

    It would be nice of it if that's what happened. Doesn't always -- if the load is very close, it may just drop voltage enough to cause various odd gremlins to appear. If that happens, you may need a larger transformer.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Nysteamer
    Nysteamer Member Posts: 22
    Hello @ratio , I have the wires connected as you described. However, the nest does not turn on with the C wire- now connected downstream to yellow in place. When I remove it, everything turns on. No clue what thats about.
  • ratio
    ratio Member Posts: 3,623
    It may be trying to fast charge it's battery. Try leaving it connected for a few hours. If that doesn't help, I guess a call to Nest support might be in order. The yellow & the blue are the correct wire colors. Any chance the xfrmr's been replaced or that schematic isn't the correct one?