Thermostat Three » Dongle

This little dongle goes between the thermostat itself and the house’s HVAC wiring. The screw terminals allow connections to the standard Red, White, Green and Yellow wires. The two extra terminals are for 6 to 10 volts DC, so the thermostat can be powered through the wall if the power is available. The white connector at the left mates with the 6-pin connector in the back of the thermostat.