Thermostat Wiring For Gas Furnace

To wire a thermostat you must first be aware of the type of system that you have in your home.

Thermostat wiring for gas furnace. If your system doesnt have a c wire youll need to run a new cable from your furnace to your thermostat to install most of the modern smart thermostat models. Furnace thermostat wiring diagram terminal letters on a thermostat and what they control the hot wire 24 volts usually red from the transformer is the main power wire to turn on or off a furnace components. The thermostat should automatically complete these connections when a set temperature is reached. Most two wire thermostats wire have a red and white wire encased in a brown insulated coating.

The most basic of systems such as an older heat only forced air gas furnace with a standing pilot light only need two wires for control. When the red wire is disconnected from w the furnace should turn off. Remove the cover of the furnace or air handler. The thermostat wiring on these systems can have very similar wiring properties.

This video is part of the heating and cooling series of training videos made to accompany my websites. Connect the white wire to the w terminal on the furnace and thermostat. For example if the red wire is connected to w on the thermostat the furnace should turn on. Goodman furnace thermostat wiring diagram chromatex.

The 18 refers to the gauge and the 5 refers to how many individual wires are inside the cable. They connect to a two wire thermostat generally a mechanical thermostat with a mercury filled ball connected to a coiled bi metal strip. This wire should go directly to the heating source whether it be a gas or oil furnace electric furnace or boiler or auxiliary heating for a heat pump. The entire bundle might be wrapped with a housing.

Strip the red and white wires back about 14 inch at both the thermostat and the furnace ends. Goodman furnace thermostat wiring diagram collections of goodman wiring diagram gas furnace thermostat trend truck in heat. White wire for w terminal. Thermostat wire is just a big spool of bundled color coded wires.

It will consist of three to eight wires of different colors including red white green yellow orange blue black etc. You should be aware that this may have changed especially if the person who wired the thermostat didnt use conventional color coding. Gas furnace thermostat wiring diagram collection. Locate where the wire bundle from the thermostat enters the furnace.