Guide to Heating, Heat Pump, or Air Conditioning Thermostats - how to find, use, adjust, repair thermostats
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Guide to Thermostats for Heating and Air Conditioning Systems - how to Find, Adjust, or Repair Thermostats - Troubleshooting & Repair Guide
Traditional wall thermostats and how they work
Detailed Guide to Round Honeywell Room Thermostats, including digital thermostats and traditional mercury-bulb thermostats
How to Set the Honeywell Room Thermostat To the Desired Temperature
How the Honeywell Room Thermostat Senses & Responds to Temperature Changes
How & Why to Adjust the Heat Anticipator on a Room Thermostat
How to Use a Mini Ammeter to Check Heat Anticipators and Thermostats for Proper Adjustment
What are the Other Little Switches For on a Room Thermostat: Heat, Air Conditioning, Off, & Fan ON OFF MAN positions
How Do I Install & Wire Up a Room Thermostat like the Honeywell Round Wall Thermostat?
Questions & Answers About Room Thermostats for Air Conditioners & Heating Systems

This article series explains selection, installation, use, setting, and adjustment of heating or cooling system room thermostats or "wall thermostats". Here we provide A Guide to Finding, Using, and Adjusting Thermostats for Heating & Air Conditioning Systems. This website answers most questions about central heating system troubleshooting, inspection, diagnosis, and repairs.

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Types of Thermostats Used to Control Air Conditioning & Heating Systems

Because some controls are used in common on hot water heat, hot air heat, and steam boilers, readers should see these other articles: see BOILER CONTROLS & SWITCHES, and also see BOILER COMPONENTS & PARTS for a detailed list of heating boiler controls, other heating system components, parts such as circulator pumps & draft regulators. If your building uses warm air heat, see FURNACE CONTROLS & SWITCHES. If your building uses steam heat see STEAM HEATING SYSTEMS. Also see Heat Won't Turn Off - Stop Unwanted Heat. Water heater thermostats are discussed separately at AQUASTAT CONTROL Functions and at Electric Water Heater Thermostats.

Readers needing to find and fix un-wanted air leaks, heat losses, or other energy wasters should see HEAT LOSS DETECTION TOOLS. Readers should see ENERGY SAVINGS RETROFIT CASE STUDY and also see HEAT LOSS DETECTION TOOLS and INSULATION INSPECTION & IMPROVEMENT for energy saving retrofit detailed guides. Also see GAS PIPING, VALVES, CONTROLS for more details on how to inspect and test LP and natural gas piping, controls, valves, and tanks.

Traditional Round Wall Thermostats & How They are Set

Photograph of an oil fired heater stack relay

Heating & Air Conditioning Thermostats where are thermostats usually located, what types of thermostatic controls are used on various heating and cooling systems, how do we find all of the thermostats, how do we set, adjust, and use thermostats

The round Honeywell (R) wall thermostat shown in this photo has been locked in a plastic enclosure to prevent people from changing its set temperature. Set temperature and how the thermostat works are described in excruciating detail below.

Room thermostats for air conditioning work and are set the same as when these devices are used for controlling heating systems. We provide lots of detail about how these devices work - see Detailed Guide to Room Thermostats below.

Traditional Rectangular Wall Thermostats and how they are set

On this wall thermostat the red pointer shows the current room temperature.

The black pointer at the center of the scale at the bottom of the little window shows the temperature that the thermostat has been "set" to.

The "Set Temperature" is the temperature that the room occupant is requesting.

Moving the thermostat adjustment lever (located at the top, side, or bottom of the thermostat depending on the model) will change the set temperature up or down, causing the heating or air conditioning system to turn on or off as needed.

See Detailed Guide to Room Thermostats below.

Programmable, Digital Room Thermostats

Digital room thermostats are illustrated in our two photographs shown here. A modern digital thermostat uses an LCD type display to show the current room temperature along with other information.

Typically the display changes in response to pushing the thermostat control buttons.

Most digital room thermostats are "programmable" - you can set the thermostat to set back the room temperature at night (in heating mode, for example) and many models allow different time and temperature settings both throughout the day and for individual days of the week as well.

Our digital thermostat shown at left indicates the time (5:43 PM) in the left side of the display and the current temperature (53 degF) in the right side of the display. With the thermostat's plastic cover "shut" it's operation is very simple, just showing up and down arrows that temporarily call for a higher or lower room "set" or "desired" temperature.

We opened the plastic thermostat cover to show additional detailed controls and instructions.

Honeywell digital room thermostat (C) Daniel Friedman

A simpler programmable Honeywell® digital room thermostat is show in our photo at left.

The thermostat is showing the current time (12:15 PM) and current room temperature (67 degF).

This unit does not provide additional buttons under a cover. But by pressing the center "Set" button the display changes to allow the user to set a desired time and temperature setting for day and night time temperatures.

We describe the operation of a typical digital room thermostat for heating or air conditioning later in this article at Questions & Answers About Room Thermostats for Air Conditioners & Heating Systems

Radiator Thermostats & Baseboard Thermostats, Automatic - TRVs

Several manufacturers provide thermostatically-controlled radiator valves (Armstrong, Danfoss, Hoffman Specialty, Jacobus (Maid'O'Mist) and others).

Automatic radiator/baseboard valves provide thermostatic controls that can be installed on individual hot water radiators, steam radiators, or heating baseboards. The automatic radiator or baseboard valve will automagically open or close to attempt to control room temperature to the desired level.

Shown at left is an adjustable individual thermostatic control installed on a hot water radiator in Molde, Norway.

For details see RADIATOR VALVES & HEAT CONTROLS This article describes these automatic or thermostatically controlled radiator valves (such as the Armstrong RV-4) that will allow you to set the desired room temperature.

Also see RADIATOR STEAM VENTS, AUTOMATIC for a description of automatic steam vents used to control the rate at which steam heat radiators will get hot. Automatic steam vents can help balance the delivery of otherwise uneven steam heat throughout a building.

Remote Control Room Thermostats for Heating and Air Conditioning

Remote control thermostats such as the unit shown at left are usually used with air conditioning or heating split systems using an outside compressor/condenser unit and one or more indoor wall-mounted cooling or heating units..

The thermostat controls in the hand-held remote control communicates with a wall-mounted air conditioner or heater using infra red signals. The open finned area at the bottom of this Sanyo control permit ambient air to enter the control for purpose of sensing the air temperature.

A control such as this Sanyo (TM) unit can be quite sophisticated and include automatic set back temperatures, timers, etc.

Heat Pump Outdoor Thermostats are used to control the turning on and off of backup heat.

Our photo (left, courtesy of Neal Renn shows the thermostatic control unit in the outdoor compressor/condenser unit of a residential heat pump.

See Heat Pump Thermostats - Outdoors and BACKUP HEAT for HEAT PUMPS and also see Detailed Case of a Heat Pump that Put out Heat when Cooling was Required

Types of Room Thermostat Temperature Sensors

Bimetallic Element thermostats

Bimetallic spring thermostat (C) Daniel Friedman

Bimetallic Element thermostats use a bimetallic spring consisting of strips of two different metals fused together, typically into a coil shape. Our photo (left) shows a coiled spring inside a mercury tube based room thermostat made by Honeywell®.

As the fused metal strip/coil is exposed to different room air temperatures, because the two metals expand or contract at different rates but are fused together, the spring "coils" or "un-coils", causing the spring end to move in response to temperature.

This movement can be used to open or close contacts to turn heating or cooling on or off in a building.

See TEMPERATURE RESPONSE of Room Thermostats for a detailed description of how bimetallic springs used in room thermosats work.

Bellows Element thermostats

Bellows Element thermostats are filled with a volatile liquid that vaporizes at temperatures typically found indoors. As the liquid vaporizes pressure inside the bellows expands, translating temperature change into the movement of a contact to turn heating or cooling on or off in response to building temperature.

Photographs of a bellows-operated line-voltage room thermostat produced by Honeywell, Inc., are found at Honeywell or in Burkhardt.

Mercury-tube Element thermostats

Mercury bulb thermostat (C) Daniel Friedman

Mercury-tube element thermostats use a glass tube containing mercury and a pair of metal contacts at one end of the tube to turn heating or cooling on or off in a building.

The mercury tube is connected to a bimetallic spring that tips the mercury tube in response to changing room air temperature.

When the tube tips in a direction that causes the mercury to move to the end of the tube containing two metal contact wires, the mercury acts as a conductor to close an electrical connection to turn heating or cooling on.

When the tube tips in the opposite direction the mercury moves off of the contacts and the switch is opened or heating /cooling are turned off.

See TEMPERATURE RESPONSE of Room Thermostats for a detailed description of how mercury tube thermosats work.

Thermostat Heaters, heat accelerators, heat anticipators

Heat anticipator control in thermostats (C) D Friedman

Some thermostats models use a source of artificial heat (a very tiny resistor or resistance heating element inside the thermostat) to force the heating system to turn off earlier than it would have if the thermostat only responded to an increase in room temperature.

In other words, the heating system itself will be turned off before the room temperature has reached the thermostat set point.

This feature is added to prevent the heating system from "overshooting" or making the room too warm - a condition that might occur due to additional heat that will be radiated into the room from radiators or heating baseboards that will continue to be warm even after the steam boiler or the hydronic boiler circulator has shut off.

To accommodate variations in heating source and distribution design, heat accelerators or heat anticipators are usually adjustable. Details are at HEAT ANTICIPATOR Adjustment.

A Guide to Using Wall-Mounted Room Thermostats - How to Set the Thermostat

Here is our photo of a traditional round Honeywell (R) round room thermostat. Detailed photos of the major components of this thermostat and a description of how they work are provided below.

Remote Control Thermostats & Remote Heat, Cooling, or Building Temperature Monitoring

A variety of remote control thermostats are offered by HVAC control manufacturers, permitting an owner to monitor, or even change building temperature control settings remotely by telephone or by web-enabled internet connection.

Also see FREEZE-PROOF A BUILDING or WINTERIZE A BUILDING.

Proliphix provides a range of energy control thermostats that offer remote temperature control via web-enabled communication between an individual and the building's HVAC controls. Also see Honeywell Controls, and White Rodgers thermostat controls.

How to Set a Room Thermostat To the Desired Temperature

Heating thermostats: Here we use a traditional, and very simple dial-type round wall-mounted thermostat as an example. Notice that the thermostat face has two temperature scales and two pointers.

The top scale on the thermostat and the red arrow shows the "set" temperature that the thermostat is asking for.

The bottom scale shows the actual room temperature.

Rotating the thermostat dial to the right (clockwise) will increase the "set" temperature. Rotating the dial to the left will decrease the "set" temperature.

Heating thermostats are a simple switch to turn on a heating furnace, boiler, or other heat source. As we explain again below about cooling, for a heating thermostat to actually cause the heating system to turn on, the ambient temperature at the thermostat must be below the set point or temperature to which the thermostat has been set.

Make sure that your thermostat has been set to the proper position for the season: cooling or heating. The air conditioner will not run with the switch set to "heating" and conversely the heating system won't run if the thermostat has been set to "cooling."

An air conditioning system thermostat is a switch to turn on or off the A/C equipment as indoor air temperature varies around the thermostat's set point. Air conditioning thermostats are typically wall mounted in the living area. The thermostat, if it's a combination unit, may have both a temperature setting switch and a switch that can be moved from "cool" to "off", or "heat" positions.

For the thermostat to call for cooling it must be in the "cool" position and the temperature set to a level below the ambient air temperature at the thermostat location. Thermostats contain an internal temperature sensor which compares the air temperature at the thermostat to the temperature called-for by the user, turning the cooling (or heating) equipment on or off as appropriate.

How to Save Heating Cost & Air Conditioning Costs by Thermostat Adjustments

Substantial heating or air conditioning cost savings can be achieved by manually setting back your thermostat when the building is unoccupied or when occupants are asleep. The thermostat is set several degrees (or more) cooler during heating season or warmer during cooling season.

The settings of thermostat "mode" switches into "heating" or "cooling" and the use of other thermostat switches to control an air conditioning blower fan or heating system blower fan are discussed in detail at Other Switches on a Room Thermostat.

Lots of websites offer calculators that will tell you how much you'll probably save in energy costs for every degree you set back your heating or cooling thermostat. Just don't set the thermostat down so low that you suffer costly damage from freezing pipes in winter or mold from high humidity in summer.

Also see Heat Won't Turn Off - Stop Unwanted Heat explanation of why heat may continue to come out of radiators or baseboards even though you have turned down the thermostat. Stop wasted heat by making sure you are not delivering heat when it is not needed or not wanted.

Questions & Answers About Room Thermostats for Air Conditioners & Heating Systems

Question: Why Does the Thermostat Display Jump Back to 83 After I set It to 68 Degrees?

My daughter had a thermostat replaced about 2 months ago [Trane unit] replaced with Honeywell digital thermo worked well.

Today she called me and said that the thermostat is saying 83 degrees and when she sets it to 72 degrees it jumps back to 83 degrees/she says the thermo is set on the cool side.

Do you know what the problem may be. Please advise - Thank you John

Reply: How a Single-Display Digital Room Thermostat Works

A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem with air conditioning systems and controls, possibly including something you were not considering. That said, there may not be any thermostat problem in the case you describe. At least not with the thermostat itself.

Our first photograph (above left) shows a basic Honeywell digital room thermostat. This one happens to be set in Heating mode but the principle of how the display works is the same in both heating and cooling modes. You'll see that the display shows the time (12:15 pm) and the current room temperature (67 degF - the house was already cool).

In normal operating mode a digital thermostat whose indicator window shows only a single temperature number displays the current room temperature that it is sensing.

When you press the temperature "set" buttons to call for a decrease in room temperature, (say for air conditioning) or an increase in room temperature (say when in heating mode), the thermostat temperature display temporarily changes to show the "set" temperature - the temperature you are calling for.

When you stop pressing the temperature "set" buttons the thermostat display returns to showing the current room temperature.

Our second digital room thermostat photo (left) shows me pressing the "set down" button until the display shows 54 degF.

This is the new "set" temperature or the temperature I am calling for at the thermostat.

Our third Honeywell digital room thermostat photo (left) shows that a moment after I removed my thumb from the "set" button the thermostat display returned to showing the current actual room temperature (67 degF).

So if the current room temperature for your daughter was actually 83 degF (or in my case 67 degF), that is the number that will show both before and after pressing the "set" buttons.

Only while the set buttons are being pressed will the display show a different temperature (the temperature you are calling for).

As the A/C turns on and begins to lower the room temperature you should see the displayed room temp number gradually drop until it reaches the set temp.

It's possible that your daughter's thermostat is therefore working normally but she simply didn't previously notice how it's display behaves. Often when we notice something for the first time we think there has been a change even if that is not the case.

Two exceptions to this description of how the display on a digital thermostat works

First: if the A/C or heating system is not working properly then even after changing the "set" temperature on the thermostat nothing will happen, or the system may run but never reach the set temperature.

Second: some digital thermostat models show not just one, but two temperatures in the display. One of these is the "set" temperature and the second is the "current" or "actual" temperature. If your daughter's display is one of this type, then it may not be working properly. But from your description it sounds as if she's got a single-display model.

Watch out: if your heating system electrical power has been shut off, when power is restored the thermostat might have "forgotten" the program that you had set into it and you'll need to re-program the device by setting the correct time and then the desired room temperature set back time, and temperature.

Backup Batteries & Default Programs for Digital Room Thermostats

Some programmable digital room thermostats include an internal battery that will allow the device to remember the program that you have set even if there has been a power outage.

All programmable digital room thermostats are designed to return to a "safe" or "standard" temperature program to be sure that heat or air conditioning will continue to work in some reasonable range in case a power outage or dead internal battery causes the thermostat to forget how it was programmed by the user.

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THERMOSTATS, HEATING / COOLING
  Types of Building & Room Thermostats
  How Thermostats Work
  Detailed Guide to Room Thermostats
  How to Set the Thermostat
  COOL OFF HEAT, Thermostat Switch
  FAN ON AUTO Thermostat Switch
  HEAT ANTICIPATOR Adjustment
  HEAT ANTICIPATOR Mini Ammeter to Check
  HEAT PUMP Thermostats - Outdoors
  INSTALL & WIRE Thermostats
  TEMPERATURE RESPONSE of Room Thermostats
  SWITCH FUNCTIONS on a Room Thermostat

Proliphix Corporate Headquarters, 3 LAN Drive Suite #100 Westford, MA 01886 Phone: +1.978.692.3375 Toll Free (U.S.): 866-IP-LIVING (866.475.4846) Fax: +1.978.692.3378 - Sales: sales@proliphix.com Marketing: marketing@proliphix.com Customer support: support@proliphix.com http://www.proliphix.com/ - quoting from the company's website:
All Proliphix Network Thermostats come with our free Uniphy Remote Management Service. This unique offering lets you monitor and control your HVAC systems by simply pointing your Browser to our secure Proliphix Web Site. Enjoy the convenience of programming a thermostat from any location, using a simple graphical interface. No computer equipment or software is required. And since Proliphix takes care of the network configuration for you, you’ll be up and running in no time. We’ll even proactively monitor your thermostats and send you an immediate email or SMS message when an HVAC problem is detected.
Honeywell Controls, the company wants you to use their contact form at this web page: http://www51.honeywell.com/honeywell/contact-support/contact-us.html
Honeywell Consumer Products, 39 Old Ridgebury Road Danbury, CT 06810-5110 - (203) 830-7800
World Headquarters, Honeywell International Inc., 101 Columbia Road, Morristown, NJ 07962, Phone: (973) 455-2000, Fax: (973) 455-4807 1-800-328-5111
White Rodgers Thermostats and HVAC controls,
Homeowner information: http://www.emersonclimate.com/en-US/brands/white_rodgers/Pages/wr-homeowner-info.aspx
Contractor information: http://www.emersonclimate.com/en-US/brands/white_rodgers/wr_contractor_info/Pages/white-rodgers-contractor-info.aspx
White Rodgers Product Catalog (don't misspell the company's name as White Rogers Thermostats) -
http://www.emersonclimate.com/Documents/thermostats.pdf - Thermostat Catalog
Domestic Central Heating Wiring Systems and Controls, 2d Ed., Raymond Ward, Newnes, ISBN-10: 0750664363, ISBN-13: 978-0750664363, Quoting from Amazon.com:
This unique A-Z guide to central heating wiring systems provides a comprehensive reference manual for hundreds of items of heating and control equipment, making it an indispensable handbook for electricians and installers across the country. The book provides comprehensive coverage of wiring and technical specifications, and now includes increased coverage of combination boilers, recently developed control features and SEDBUK (Seasonal Efficiency of Domestic Boilers in the UK) boilers ratings, where known.
In addition to providing concise details of nearly 500 different boilers fuelled by electric, gas, oil and solid fuel, and over 400 programmers and time switches, this invaluable resource also features numerous easy-to-understand wiring diagrams with notes on all definitive systems. Brief component descriptions are provided, along with updated contact and website details for most major manufacturers.
"Automatic Oil Burner Controls - Thermostats", Domestic and Commercial Oil Burners, 3rd Ed., Charles H. Burkhardt, McGraw Hill, 1969 (and later editions), ASIN B0000EG4Y8

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.

The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 2010, $69.00 U.S., is available from Carson Dunlop. The Home Reference Book is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. InspectAPedia.com ^® author/editor Daniel Friedman is a contributing author. Field inspection worksheets are included at the back of the volume.

Carbon Monoxide Gas Toxicity, exposure limits, poisoning symptoms, and inspecting buildings for CO hazards
DUST CONTAMINATION FROM HVAC? An Investigation of Indoor Dust Debris Blamed on a Heating/Cooling System Reveals Carpet Dust
Fuel Oil & Oil Heating Magazine, 3621 Hill Rd., Parsippany, NJ 07054, 973-331-9545
Goodman Furnace High Temperature Plastic Vent HTPV safety recall US CPSC notice
Home Heating System Should Be Checked [for proper venting and for CO Carbon Monoxide Hazards - DJF]
Inspection Procedures for Oil-Fired Heating Systems Detailed step by step approaches for inspecting complex systems]
Lennox Pulse Furnace Safety Inspection/Warranty Program: Carbon Monoxide Warning
Oil Tanks - The Oil Storage Tank Information Website: Buried or Above Ground Oil Tank Inspection, Testing, Cleanup, Abandonment of Oil Tanks
Oil Tanks Above Ground, UL Standards, guidance for home owners, buyers, and inspectors
Plastic Heating Vent Pipe & Other Heating Safety Recall Notices
Weil McLain Model GV Gas Boiler/gas valve CPSC recall/repair
Domestic and Commercial Oil Burners, Charles H. Burkhardt, McGraw Hill Book Company, New York 3rd Ed 1969.
National Fuel Gas Code (Z223.1) $16.00 and National Fuel Gas Code Handbook (Z223.2) $47.00 American Gas Association (A.G.A.), 1515 Wilson Boulevard, Arlington, VA 22209 also available from National Fire Protection Association, Batterymarch Park, Quincy, MA 02269. Fundamentals of Gas Appliance Venting and Ventilation, 1985, American Gas Association Laboratories, Engineering Services Department. American Gas Association, 1515 Wilson Boulevard, Arlington, VA 22209. Catalog #XHO585. Reprinted 1989.
The Steam Book, 1984, Training and Education Department, Fluid Handling Division, ITT [probably out of print, possibly available from several home inspection supply companies] Fuel Oil and Oil Heat Magazine, October 1990, offers an update,
Principles of Steam Heating, $13.25 includes postage. Fuel oil & Oil Heat Magazine, 389 Passaic Ave., Fairfield, NJ 07004.
The Lost Art of Steam Heating, Dan Holohan, 516-579-3046 FAX
Principles of Steam Heating, Dan Holohan, technical editor of Fuel Oil and Oil Heat magazine, 389 Passaic Ave., Fairfield, NJ 07004 ($12.+1.25 postage/handling).
"Residential Steam Heating Systems", Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
"Residential Hydronic (circulating hot water) Heating Systems", Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
"Warm Air Heating Systems". Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
Heating, Ventilating, and Air Conditioning Volume I, Heating Fundamentals,
Boilers, Boiler Conversions, James E. Brumbaugh, ISBN 0-672-23389-4 (v. 1) Volume II, Oil, Gas, and Coal Burners, Controls, Ducts, Piping, Valves, James E. Brumbaugh, ISBN 0-672-23390-7 (v. 2) Volume III, Radiant Heating, Water Heaters, Ventilation, Air Conditioning, Heat Pumps, Air Cleaners, James E. Brumbaugh, ISBN 0-672-23383-5 (v. 3) or ISBN 0-672-23380-0 (set) Special Sales Director, Macmillan Publishing Co., 866 Third Ave., New York, NY 10022. Macmillan Publishing Co., NY
Installation Guide for Residential Hydronic Heating Systems
Installation Guide #200, The Hydronics Institute, 35 Russo Place, Berkeley Heights, NJ 07922
The ABC's of Retention Head Oil Burners, National Association of Oil Heat Service Managers, TM 115, National Old Timers' Association of the Energy Industry, PO Box 168, Mineola, NY 11501. (Excellent tips on spotting problems on oil-fired heating equipment. Booklet.)
Links to our list of additional information on heating system inspection, repair, maintenance
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Types of Thermostats Used to Control Air Conditioning & Heating Systems

Traditional Round Wall Thermostats & How They are Set

Traditional Rectangular Wall Thermostats and how they are set

Programmable, Digital Room Thermostats

Radiator Thermostats & Baseboard Thermostats, Automatic - TRVs

Remote Control Room Thermostats for Heating and Air Conditioning

Types of Room Thermostat Temperature Sensors

Bimetallic Element thermostats

Bellows Element thermostats

Mercury-tube Element thermostats

Thermostat Heaters, heat accelerators, heat anticipators

A Guide to Using Wall-Mounted Room Thermostats - How to Set the Thermostat

Remote Control Thermostats & Remote Heat, Cooling, or Building Temperature Monitoring

How to Set a Room Thermostat To the Desired Temperature

How to Save Heating Cost & Air Conditioning Costs by Thermostat Adjustments

Questions & Answers About Room Thermostats for Air Conditioners & Heating Systems

Question: Why Does the Thermostat Display Jump Back to 83 After I set It to 68 Degrees?

Reply: How a Single-Display Digital Room Thermostat Works

Two exceptions to this description of how the display on a digital thermostat works

Backup Batteries & Default Programs for Digital Room Thermostats

Questions & Answers regarding this article

Ask a Question or Search InspectAPedia

Technical Reviewers & References

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair