HVAC ITEMS, My hardware:
Hyrdro-therm HC-145 boiler for hydroponic baseboard heat ~ 50 years old
24-volt transformer with R, C, W, G terminals
White Rodgers Zone Valves, Mode number 1311-102 times TWO.
One for upstairs heat
One for downstairs heat
Terminal 4 = white wire ---à W1 = “call for heat”. Causes valve to rotate open and furnace to ignite.
Terminal 5 = red wire ------à Rh = power
Terminal 6 = green wire. ---à Y1 = “call to stop heat” and turns furnace off.
Was working fine until put in Nests GA02082-US thermostats in place of upstairs and downstairs Honeywell thermostats.
Now will actuate Call For Heat and system works to warm house.
DOES NOT CALL TO STOP HEAT! No activity to Green wire by Nest Thermostat.
Old functioning Honeywell thermostat had White to W1. Red to Rh. And Green to Y1.
Same wiring used with Nest thermostat.
Getting an N260 Code form Nest, related to needing a “C” wire, which I can handle.
QUESTIONS:
- How do I get power to the Green wire to call to stop heat by shutting valve on zone valves?
- I see on the internet that people are using an Isolation Relay. But I don’t see a wiring diagram anywhere. How do I wire the isolation relay to the thermostat and the boiler’s zone valves?
- Is it possible to program the Nest thermostat to power the green wire to call for stopping the Heating cycle?
