Programmable Thermostats
Get Rebates,
Incentives & Services
Introduction
It can be expensive to leave the temperature inside your home or office constant day and night. It is more economical to turn the heat or air conditioning down when no one is around, or at night when you are asleep without sacrificing any comfort. Programmable thermostats allow you to do this automatically. New buildings in California with a central heating and cooling system must come with an automatic set-back thermostat. If you have an older building that doesn't have one, you can usually replace your existing wall thermostat with a set-back model very easily.
Savings from using a programmable thermostat can be impressive. Recent studies show that proper usage of a programmable thermostat can cut a home or business' heating costs by approximately 25%. In the summer, such devices may shave cooling costs 15 to 25%. For homeowners, this translates to savings of up to $160 annually. Actual savings will depend on such factors as the climate, the amount of insulation in a home or business, the temperature one sets the thermostat and the rate structure of the utility company.
Technology Options
A thermostat is a temperature-sensitive switch that controls a space conditioning unit or system, such as a furnace or air conditioner, or both. When the indoor temperature drops below or rises above the thermostat setting, the switch moves to the "on" position, and your furnace or air conditioner runs to warm or cool the indoor air to the setting you selected for your comfort. A thermostat, in its simplest form, must be manually adjusted to change the indoor air temperature.
'ENERGY STAR', qualified programmable thermostats allow you to program multiple settings, allowing "at home and away from home" schedules for the weekdays and a different one for the weekend. Qualified models come pre-programmed for typical schedules with comfortable but energy-saving settings. Some models may feature full seven-day programming, enabling you to customize the operation of your heating and cooling system for any day of the week. By maintaining the recommended default settings, a programmable thermostat can pay for itself in energy saved within less than one year (average prices ranging from $30 to $150; savings can be $160/year).
![]() |
||
![]() |
||
![]() |
||
Most modern programmable thermostats perform one or more of the following energy control functions: | ||
|
![]() |
|
![]() |
||
![]() |
Most programmable thermostats have liquid crystal temperature displays. Some have back-up battery packs that eliminate the need to reprogram the time or clock in case of a power failure. New programmable thermostats can be programmed to accommodate life style and control heating and cooling systems as needed. Manufacturers are offering simpler programming instructions to allow you to adjust their default settings to maximize savings and comfort.
Types of Automatic and Programmable Thermostats
There are five basic types of automatic and programmable thermostats. Most range in price from $30 to $150, except for occupancy- and light-sensing thermostats, which cost about $200.
Electromechanical (EM) thermostats typically have manual controls, such as movable tabs to set a rotary timer and sliding levers for night and day temperature settings. These thermostats work with most conventional heating and cooling systems, except heat pumps. EM controls have limited flexibility and can store only the same settings for each day, although at least one manufacturer has a model with separate settings for each day of the week. EM thermostats are best suited for regular schedules.
Digital thermostats are identified by their LED or LCD digital read-out and data entry pads or buttons. They offer the widest range of features and flexibility, and digital thermostats can be used with most heating and cooling systems. They provide precise temperature control, and they permit custom scheduling. Programming some models can be fairly complicated; make sure you are comfortable with the functions and operation of the thermostat you choose. Remember, you won't save energy if you don't set the controls or if you set them incorrectly.
Hybrid systems combine the technology of digital controls with manual slides and knobs to simplify use and allow for flexibility. Hybrid models are available for most systems, including heat pumps.
Occupancy thermostats maintain the set-back temperature until someone presses a button to call for heating or cooling. They do not rely on the time of day. The ensuing preset "comfort period" lasts from 30 minutes to 12 hours, depending on how you've set the thermostat. Then, the temperature returns to the set-back level. These units offer the ultimate in simplicity, but lack flexibility. Occupancy thermostats are best suited for spaces that remain unoccupied for long periods of time.
Light-sensing heat thermostats rely on the lighting level preset by the owner to activate heating systems. When lighting is reduced, a photocell inside the thermostat senses unoccupied conditions and allows space temperatures to fall 10°F below the occupied temperature setting. When lighting levels increase to normal, temperatures automatically adjust to comfort conditions. These units do not require batteries or programming and reset themselves after power failures. Light-sensing thermostats are designed primarily for stores and offices where occupancy determines lighting requirements and therefore heating requirements.
Efficiency Benefits
ENERGY STAR qualified programmable thermostats must have two separate programs with different settings for weekdays and weekends, and at least four temperature settings for each day. This allows you to customize your heating and cooling program for only the hours that you will need it. They also must be able to maintain room temperature within 2°F of desired temperature.
The savings that you realize from upgrading to an ENERGY STAR thermostat depends on how you use it. For example, by turning your thermostat back 10°F to 15°F for eight hours a day, you can save about 5% to 15% a year on your heating bill a savings of as much as 1% for each degree if the set-back period is eight hours long. The percentage savings from set-back is greater for buildings in milder climates than for those in more severe climates. In the summer, you can achieve similar savings by keeping the indoor temperature a bit higher when you're away than you do when you're home. If the pre-programmed settings are kept in place when you buy your thermostat, you can save up to $160 on your yearly energy bills.
Manufacturers
Aprilaire, Honeywell and Hunter Fan Company are some of the manufacturers of ENERGY STAR qualified programmable thermostats. For a complete list, visit the ENERGY STAR website.
Purchasing Tips
There are many factors to consider before you purchase a programmable thermostat. Because they are relatively new to the market, you should do some research before you buy.
![]() |
|
![]() |
Some features to look for when buying a new programmable thermostat:
![]() |
|
![]() |
Some tips to help maximize your energy savings:
![]() |
|
![]() |