West Shore > Homewood > McBride Cabin > Notes > Ecobee > 2 wire install
Option 4 from Heat only 2-wire boiler/furnace installations for ecobee thermostats – ecobee Support

OPTION 4. FAST-STAT COMMON MAKER WITH R/W contacts

Option 4 entails using your existing two thermostat wires and installing a FAST-STAT Common Maker for furnace/boilers with R & W connections. You will not be required to run a new wire from your thermostat to your furnace/boiler.

ecobee-common-maker.jpg

Below is a diagram illustrating how the ecobee would be wired with the common maker in this scenario.

Note: The R wire must go into RC instead of RH.ecobee-common-maker-r-w.png />

A C (common) wire must be identified at the furnace/boiler system for the FAST-STAT to connect to. If you find your system does not have a C (common) terminal, you will need to identify where the C wire can be connected to. Every furnace/boiler that has a 24VAC transformer will have a common terminal—just trace the 2 low-voltage wires and see where they connect to. If there is an existing connection point, then tap the FAST-STAT C wire at this point. Sometimes cutting/stripping the common wire for splicing the FAST-STAT C wire may also be required.

Always make certain you are connecting to the (secondary) low voltage side and NOT the (primary) line voltage side of the transformer—otherwise immediate damage will result! We recommend consulting with a licensed contractor if you're not comfortable re-wiring with high voltage equipment.