If you have a two stage heat pump then you will also utilize terminal y2 for the second stage.
Single stage furnace thermostat wiring.
How to choose the right furnace thermostat.
A basic two wire thermostat can be compared to a simple single pole switch that you will find throughout your home only instead of you turning the switch on and off as required a mechanical or electronic temperature controlled mechanism is the operator of the switch.
One which is common is the single stage heating system and the other one is multi stage heating system.
The thermostat you purchased is designed for a single stage system such as an air conditioner and a single stage gas furnace.
A two stage thermostat may need more wires than your current programmable thermostat.
Strip the brown thermostat wire back one half inch and connect it to the w2 terminal on the furnace.
A two stage or variable speed system may only be operating at a single speed because the thermostat or control system doesn t allow for two stage wiring.
Conventional single stage systems will have one wire leading into w or w1 terminal for heating and one wire leading into y or y1 terminal for cooling.
So that s the easiest way to identify single stage conventional hvac systems which would be furnace based or boiler based.
So you may have to fish an additional four strand cable from the furnace room to the thermostat location photo 1.
The first and foremost thing you must do is to check what kind of heating system you are using at your home.
1 know your heating system.
Single stage hvac system thermostat source.
The e and w2 hook ups are for the emergency heat relay and auxiliary heat control respectively.
The new thermostat doesn t have these because it isn t designed for this type of installation.
Cadet 16 7 amp 120 208 240 volt single pole electronic 7 day programmable wall thermostat in white.
This controls the second stage of heating.
A dual fuel system which is comprised of a gas furnace and a heat pump should be connected to a thermostat or control system that can accommodate the specific heating set points.
Furthermore this thermostat wiring diagram is specifically for a system with two transformers your system likely only has one transformer as most typical residential systems only use a single transformer for control.
If not connect them in this manner.
Basically heating furnaces are of two types.
The terminals are usually marked r and w.