How to Choose a 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.

Multi Stage Heat Pump: (Most advanced thermostat)
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 matter of personal preference!

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.

Step Two: Determine the features you desire

Programmable
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.

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

Mechanical
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.

See All Thermostats