Click here to Find a Contractor in your area.
Welcome! Here are some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.

2 Wire Thermostat Connection for an EcoBee Wifi Thermostat on an old Weil McLain Model H-4 Boiler

I could not find much information on the Internet dedicated to this topic, so I am sharing what I for others who endeavor into such a task. The objective herein was to replace an old 2 wire mercury thermostat with a modern ecobee3 thermostat, and in doing so provide a new common line for the wifi thermostat utilizing the existing 2 wire design. I made use the FAST-STAT common maker system for this installation. Attached is the wiring diagram, with modifications, as a resource for others in their endeavors.

Comments

  • hot rod_7hot rod_7 Posts: 8,824Member
    excellent info, thanks for taking the time to figure it out.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
Sign In or Register to comment.

Welcome

It looks like you're new here. If you want to get involved, click one of these buttons!