Thermostat Buying Guide
Shopping for a thermostat? There are many factors to consider when deciding which thermostat
is right for you. The main differences are programmability, the applications they are used for,
number of stages, user interface, mount, voltage, changeover type and ability to work with sensors.
Programmable thermostats save energy, save you money and maximize comfort based on your
unique schedule! They typically have four setpoints, allowing you to set different temperatures for
the morning, daytime, evening and over night. Most programmable thermostats can operate in a
non-programmable mode if you choose not to set a program.
Setting Description
7 Day Different settings for every day of the week
5-1-1 Day Monday thru Friday setting, Saturday setting, Sunday setting
5-2 Day Weekday setting, Weekend setting
Non-programmable Temperature can only be adjusted manually
Heat Only- works only with a single heating source
Cool Only- works only with a single cooling source
Single Stage Heat/Cool- controls one heating source and one cooling source
Multi-Stage Heat/Cool- controls multiple heating and cooling sources
Electric Heat/Line Voltage*- controls electric baseboard and electric heaters
Heat Pump*- used in heat pump applications, such as air source heat pumps and ground source heat  •pumps; they can be single or multi-stage
Fan Coil*- work with fan coil units, such as unit ventilators
Millivolt- used to regulate systems that utilize a pilot light rather than an electrical circuit, such as a gas-fired  •water heater
 •* Note: If you have a heat pump, electric heat or millivolt system, it is important to select a thermostat that is  • •compatible with this specific type of system.
Number of Stages
This refers to the number of heating or cooling sources that may be controlled by a single thermostat. For example, if a system contains baseboard heat, a hot air system and air conditioning, then there are two heating stages and one cooling stage. In this example, a 2 heat/1 cool thermostat should be installed. Note: If you have auxiliary heat (backup heat, such as a fan coil or baseboard), that counts as a second heating source.
The number of stages may be written in several different ways. The most common are 2H/1C or 2 Heat/2 Cool; both mean that there are two heat sources and one cool source. The number of stages can vary from single heat or single cool up to 4 Heat/3 Cool on a single thermostat.
User Interface
Thermostats are operated using a digital touchscreen, buttons with a digital screen, or simple mechanical dial. Our most popular touchscreen thermostat is the Honeywell TH8110U1003.
Touch Screen Digital Button Mechanical
TH8110U1003 TH6110D1005 T87K1007
Thermostats may be mounted horizontally or vertically depending on personal preference and space constraints.
Horizontal Vertical
TH4110D1007 TH2110D1009
Some digital thermostats have a large display, which makes it even easier to read.
Large Display Standard Display
TH4110D1007 TH6110D1005
Thermostats run on either line voltage or low voltage.The easiest way to tell which type you need is by looking at the wire. If it is a very thin wire (like a doorbell or a speaker wire), you will need a low voltage thermostat. If it is a heavy wire, you will need a line voltage thermostat.
Changeover Type
Thermostats either have automatic changeover or manual changeover. Thermostats with auto changeover switch from heat to cool automatically depending on the indoor temperature, while thermostats with manual changeover will remain on either heat or cool until you change it.