2 Stage Furnace Thermostat Wiring
A two stage furnace works like this.
2 stage furnace thermostat wiring. Locate where the wire bundle from the thermostat enters the furnace. Your thermostat calls for heat and the furnace kicks on low. How many thermostat wires needed for 2 stage stat. Basic checks two stage furnace air conditioner thermostat control problem you may also want to check the thermostat wire to make sure it is good especially at the terminations.
Thermostat wire is 18 gauge solid copper wire and over time it can become brittle. For this extra stage you need to connect one additional wire to your furnace and your thermostat. My old thermostat has 4 wires connected to it with 2 extra ones unused in the wall. Your current thermostat is designed to allow independent control of the outside heat pump and the inside auxiliary furnace two stage on the heat side.
This one explains the 2 stage thermostat and how it is wired. It will consist of three to eight wires of different colors including red white green yellow orange blue black etc. Im putting a new 2 stage variable speed furnace in my house and i want to upgrade the thermostat to a 2 stage one to better control it. They connect to a two wire thermostat generally a mechanical thermostat with a mercury filled ball connected to a coiled bi metal strip.
The entire bundle might be wrapped with a housing. Sometimes the wire could look good but it is broken. It might be necessary to remove a cover over the control board to expose the wiring connections. 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.
This video is part of the heating and cooling series of training videos made to accompany my websites.