Honeywell RTH8580WF manual Wiring, Installing your thermostat

Installing your thermostat

Note: The Wi-Fi thermostat requires a C wire to operate. The C, or common, wire brings 24 VAC power to the thermostat. Many older mechanical or battery operated thermostats do not require a C wire. If you don’t have a C wire, try:

•Looking for an unused wire that is pushed into the wall. Connect that wire to C and check that it is connected to the 24 VAC common at your heating/ cooling system. Check the video section at wifithermostat.com.

•Installing a new wire. If required, contact a contractor to install a new wire (go to wifithermostat.com to locate a contractor in your area).

Wiring

For conventional heating/cooling systems (natural gas, oil or electric furnace, air conditioner), see page 16. See “Glossary” on page 65 for further definition.

For a heat pump system, see page 17. See “Glossary” on page 65 for further definition.

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