All Categories


Become an Appliance Expert. Subscribe to our Knowledge Base!

3 Steps to Choosing the Right Thermostat

Step One: Determine what system you have

Single Stage: (Traditional gas heat and electric AC gystems)
Single-stage heating means that your furnace only has one level of heat output. An example would be if you only have a gas, forced air heater, or if you have an electric AC system with a separate heating system. This is the most common type of system all over the country. If you already have a thermostat, then you will generally have 6 wires or less coming from your wall.

Multi Stage: (More than one level of heating or cooling)
Multi Stage heating means that you have two levels of heat in your home. You will perhaps have a furnace and another method of heat like a solar panel. The second level of heat is commonly referred to as an emergency heat setting. Therefore, because the low setting is adequate to meet household-cooling or heating demands 80% of the time, the multi-stage unit runs for longer periods and provides more even heat distribution.

Heat Pump: (If you have this system, you will know)
A heat pump is a single system that does both your heating and cooling. When a heat pump is used you will not have a separate air conditioning system because the heat pump can do both operations. A heat pump is used as the emergency heat for multi stage units because it can produce heat faster than any other unit and heat up your home faster on very cold days; these systems are popular all over the county but especially in the Northeast. The Heat Pump thermostat will generally have more than 5 wires and almost always with a W2 and a C or X wire.

thermostat-wiringMulti Stage Heat Pump: (Most advanced)
This system uses more than one system just like the multi stage but it uses a heat pump as the emergency heating or cooling. You will have a typical heating or cooling unit and rely on the heat pump to help your typical system heat or cool faster and more efficiently. You will have to switch the thermostat to emergency heating or emergency cooling for this to work but it is more efficient and can make your home more comfortable faster.

Line Voltage: (Uses direct voltage)
A line voltage system uses direct current instead of only 24 volts like the typical thermostat of today's newer homes. This type of thermostat is used in older homes that use direct voltage. The power wires are thicker and they generally run either 120 or 240 volts on direct current. Line voltage electric heat thermostats are common in older construction especially with baseboard heaters and with electric heaters. They are NOT used with gas heating (gas heaters are generally single stage systems). Most line voltage systems are mechanical rather than digital programmable. Depending on the voltage of the thermostat and the home the thermostat will use either 2 or 4 wires black and red wires.

-Double Pole or Single Pole?

A line voltage single pole thermostat is a system where you cannot shut off the power to your system. The thermostat connects to the electricity via 2 wires. Essentially, you can turn the temperature far down to prevent the heat coming on but if your home happens to get to that low temperature your thermostat will turn on the heat. These types of systems are good for vacation homes in cold climates to make sure that pipes don't freeze.

A line voltage double pole thermostat is the type of system you would want if you need to entirely shut off power to your unit. This thermostat will connect to your power via 4 wires. The double pole system utilizes a circuit that can completely turn off, similar to an electrical device that has a turn dial that if turned all the way to one side will "click" and completely turn off. This type of system works perfectly for those that shut off their homes completely at night, or have summer homes that they like to power down. Some homeowners insurance policies and building codes require this type of system.

Step Two: Determine the features you desire

A programmable system has different types of setting depending on the type of programmable. You can have 5-2, 2-2-1, or 7 day programming capabilities. These are the separate types of day combinations that exist for thermostats. These styles have even evolved to include touch screens.

This style is not programmable but it has a digital read out similar to your digital alarm clock.

These systems work with a mercury switch that does the job of a relay switch today. They are not able to be programmed and are the original technology of thermostats.

Step Three: Choose the best model

Choosing the right model will depend on the features you desire and the style you prefer. Below we have included a few popular choices from our site. If you need additional assistance determining what thermostat will work best for you consider using our interactive thermostat finder or feel free to call us at 1-800-734-0405 and we'll gladly guide you through the selection process.


Honeywell TH8320

TL8230A1003 Image1

Honeywell TL8230A1003


Robert Shaw 9620


Honeywell T8775A

See All Thermostats

Like our article? Subscribe for more!