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Honeywell WIFI thermostat RTH9580WF

Ross13 Member Posts: 4
I have a 2 zone oil heat system.  I currently have LuxPro thermostats.  The three wires coming out of the wall are the following:

RED - connected to RH

WHITE - connected to W

GREEN - NOT USED (not shown in picture)

BLACK - Jumped between RH & RC

The new Honeywell WIFI thermostat states you need a "C" wire for power.  I went down to the Burhnam furnace to check Honeywell board and the GREEN wire is not connected to anything.  I also do not see anywhere on the board a "C" to connect to?

Any suggestions.  Attached are 3 pictures. In order, Honeywell control board @ the furnace, current LuxPro t-stat, & the new Honeywell t-stat.


  • Tony Massi
    Tony Massi Member Posts: 86

    You can check out the You Tube video on this thermostat installation. The thermostat needs the C wire to power thermostat. It has to have power other than batteries the old thermostat had.  I would say you can't use this thermostat with the L8124 control you have.
  • JStar
    JStar Member Posts: 2,752

    Add a switching relay with a Common terminal We use the Honeywell R8845U.
  • Tony Massi
    Tony Massi Member Posts: 86

    I see where you could use this control as long as you have 3 wires at the thermostat.