Welcome to the world of comfort and energy savings with your new Honeywell Programmable Thermostat. Your new thermostat will automatically control the temperature in your home, keeping you comfortable while saving energy.
Weekday/Weekend (5-day/2-day)
Programmable Heat and/or Cool
Low Voltage (20 to 30 Vac)
Thermostat and Mounting Plate
Model CT2800
® U.S. Registered Trademark Copyright © 2003 Honeywell International Inc. All Rights Reserved
MERCURY NOTICE If you are removing an old thermostat that contains mercury in a sealed tube (Fig. 1), do not place the old thermostat in the trash. Contact your local waste management authority for instructions regarding recycling and the proper disposal of the old thermostat.
Make sure that the CT2800 is the correct thermostat for your heating/cooling system. Read the compatibility chart below to determine which system you have. If your system is not compatible with the CT2800, the table recommends an alternate Honeywell model. If you are unsure what type of thermostat is right for your system, visit us on the Web at www.honeywell.com/yourhome or call Honeywell Customer Care at 1-800-468-1502.
Heating/Cooling System | Compatible with CT2800? | Alternate Model |
Conventional Single stage systems that include warm air furnaces and hot water. | Yes | |
Electric Baseboard Electric-powered heating strips located just above the floor, usually 120 to 240 volts. | No | CT1950 for 240 volts |
Heating/Cooling System | Compatible with CT2800? | Alternate Model |
Steam A steam boiler with radiator heat. | No | CT3600 |
Heat Pump Heating and cooling are produced from the same outdoor unit (compressor) with no auxiliary or backup heat. | No | CT3600 |
Multistage Heat Pump Heating and cooling are produced from the same outdoor unit (compressor) with auxiliary or backup heat. | No | CT3611 |
Multistage Conventional A heating or cooling system with more than one stage. | No | See your contractor |
Step 1. Prepare for Installation
Required Tools and Supplies | Optional Tools |
• Two AA alkaline batteries. Honeywell recommends Energizer® batteries. • Screwdriver. • Hand or power drill with 3/16-inch or 7/32-inch drill bit. • Pencil. | • Wire cutter/stripper or sharp knife. • Level. • Electrical tape. |
Step 2. Remove Old Thermostat
Step 3. Install Mounting Plate
Check your progress The mounting plate is now mounted on the wall and should look like Fig. 7.
Step 4. Set Thermostat for Your Type of Heating System
IMPORTANT:
Setting your thermostat cor-rectly for your type of heating system allows it to maintain accurate temperature control, minimize swings in the tem-perature of the room, and efficiently run the fan.
Type of System | DIP Switches 1 and 2 | Fuel Switch |
Warm air, gas, or oil heating system with an efficiency rating under 90%. (The furnace efficiency rating should be on the furnace.) | Use factory setting 1–On; 2–On | F |
High-efficiency furnace such as a 90% or greater AFUE (Average Fuel Utilization Efficiency) unit | 1–Off; 2–On | F |
Hot water boiler | 1–Off; 2–On | F |
Electric furnace | 1–On; 2–Off | E |
Step 5. Wire Thermostat Terminals
Step 6. Mount Thermostat
Step 7. Install the batteries
IMPORTANT: Batteries must be installed for programming and operation of the thermostat and heating/cooling system. Honeywell recom-mends using Energizer® batteries.
Check your progress When the batteries are installed correctly, the digital display flashes all entries once, then begins to flash a default time and the current temperature (Fig. 14). The flashing continues until you begin to program the thermostat. You are now ready to program the thermostat. See Programming section.
Clock thermostat with C or C1 terminals
A clock thermostat has one or two extra wires attached to the C or C1 terminals that allow the clock to operate. These wires are not used during the installation of your new CT2800 Thermostat and must be insulated from each other to avoid damaging your electrical circuit.
Six or more wires
If your old thermostat has six or more wires (excluding clock wires attached to the C or C1 terminals), your heating/cooling system is most likely a variation of a heat pump or multistage system. Your CT2800 Thermostat will NOT work with such systems and should be returned to the place of purchase. See the thermostat compatibility table for information about which programmable thermostat will work with your system.
Three thermostat wires
If you have three wires for heating only and can operate the fan using the fan ON switch, the CT2800 Thermostat will work with your system. Continue the installation procedure.
If you have a three-wire heating-only system and cannot operate the fan using the fan ON switch, the CT2800 Thermostat will probably NOT work with your system. Contact your heating contractor for installation assistance.
Wires that are not connected to old thermostat
If there are extra wires that do not connect to your old thermostat, do not label them. You will not connect these wires to your new thermostat. Tape off the wires individually with electrical tape and place them where they will not interfere with the operation of the new thermostat. Continue the installation procedure.
Five wires connected to old thermostat
Your new thermostat has a factory-installed metal jumper between the R and Rc terminals (Fig. 15). Remove the jumper before wiring the R and Rc terminals.
Thermostat C Terminal
This thermostat does not use the C wiring terminal.
Old thermostat terminals that do not match new thermostat terminals
Use the table below to wire the new thermostat.
Old Thermostat Terminal | Connect to New Thermostat Terminal | Description |
R, RH, 4, V | R* | Power |
Rc, R | Rc* | Power for cooling |
W, W1, H | W | Heat |
Y, Y1, M | Y | Cooling |
G, F | G | Fan |
O | Do not continue installation | Changeover in cool (O terminal) or changeover in heat (B terminal). You have a single-stage heat pump or zoning system. Select an alternate thermostat model. |
B | ||
C, X, B | Do not connect | Transformer common. |
W2, H2 | Do not continue installation. | Second stage heat (W2, H2) or second stage cooling (Y2). You have a multistage heating/cooling system. Select an alternate thermostat model. |
Y2 |
Remove factory-installed jumper between R and Rc terminals in 5-wire systems.
Faceplate Illustration and Description
Step 1. Set Current Time and Day
Step 2. Learn About Programming Features
Your CT2800 Thermostat allows you to program schedules for both a heating season and a cooling season.
For each season, you can set up to four program periods for the weekdays (Monday–Friday), and up to two program periods for the weekends (Saturday and Sunday). The program periods are defined in the following table.
Program Period | Description | When Available |
WAKE | The time when you get up and get ready to leave your home. You can set the system at a comfortable temperature for this period. | Weekdays and weekend |
LEAVE | The time when you are regularly away from home. You can set up an energy-saving temperature for this period. | Weekdays only |
RETURN | The time between returning home and going to bed. You can set the system at a comfortable temperature for this period. | Weekdays only |
SLEEP | The time when you are sleeping. You can set up an energy-saving temperature for this period. | Weekdays and weekend |
Step 3. Program Heating Schedule
Heating Schedule | Program Period | WAKE | LEAVE | RETURN | SLEEP |
Suggested Settings | Time | 6:00 AM | 8:00 AM | 6:00 PM | 10:00 PM |
Temp | 70°F (21°C) | 62°F (16.5°C) | 70°F (21°C) | 62°F (16.5°C) | |
Weekday (Mon–Fri) | Time | ||||
Temp | |||||
Weekend (Sat–Sun) | Time | ||||
Temp |
Step 4. Program Cooling Schedule
Cooling Schedule | Program Period | WAKE | LEAVE | RETURN | SLEEP |
Suggested Settings | Time | 6:00 AM | 8:00 AM | 6:00 PM | 10:00 PM |
Temp | 78°F (25.5°C) | 85°F (29.5°C) | 78°F (25.5°C) | 82°F (28°C) | |
Weekday (Mon–Fri) | Time | ||||
Temp | |||||
Weekend (Sat–Sun) | Time | ||||
Temp |
Step 5. Check System
Verify that your heating system works
IMPORTANT: To avoid damaging the compressor in the air conditioner, do not operate the cooling system when the tem-perature outdoors is below 50°F (10°C).
Change Clock for Daylight/Standard Time
Set Fan and System Switches
The switches on the bottom of the thermostat faceplate control the operation of your fan and the heating and cooling system. Set the Fan switch first and then set the System switch.
Switch | Setting | Result |
Fan | Auto | A single-speed fan turns on automatically with the air conditioner or furnace. A two-speed fan usually runs on high with the air conditioner and on low with the furnace. Auto is the normal setting for most homes. |
On | The fan runs continuously. Use this setting for improved air circulation during special occasions or for more efficient air cleaning.
NOTE: In a heat-only system, the fan runs continuously only if the fan wire has been con- nected to the G terminal on the back of the thermostat. | |
System | Cool | The thermostat controls your air conditioning system. |
Off | Both the heating and air conditioning systems are off. | |
Heat | The thermostat controls your heating system. |
As the batteries run low, your thermostat shows the following in the digital display:
If you see: | Batteries are: | You should: |
Flashing “bAt Lo” | Low | Replace the batteries as soon as possible, within the month. |
Blank display | Dead | Replace the batteries immediately. Your heating/cooling system is not operating. |
NOTE: Make sure the System switch is set to either HEAT or COOL before making any changes to the schedule.
Change the temperature temporarily
Hold a temperature indefinitely
Use the Hold Temp feature when you want to maintain a constant temperature indefinitely, such as when you go on vacation.
Check the current programmed temperature
Check programs
Press
Cancel a program
Change a program permanently
Follow steps for programming heating schedule or programming cooling schedule.
If… | Then… |
Display does not come on | • Make sure the batteries are fresh and installed correctly. • Set System switch to Off. Remove batteries and insert backward for 5-10 seconds to reset thermostat. Replace batteries correctly; display should come on. |
Temperature display does not go lower than 45°F (7°C) or higher than 88°F (31°C) during programming. | • Temperature limit setting is reached; range is 45°F to 88°F (7°C to 31°C). |
Display shows flashing “bAt Lo.” | • The batteries are low; replace them as soon as possible. • If “bAt Lo” continues to display after replacing batteries, set System switch to OFF and insert batteries backward for 5-10 seconds. Replace batteries correctly; display should come on. |
Temperature change occurs at wrong times | • Check program times for period in question. Be sure AM and PM indications are correct. Make sure current day and time are correct. Reprogram if necessary. |
If… | Then… |
Heating does not come on | • Check that the System switch is set to HEAT. • Check the system fuse or circuit breaker and replace or reset if necessary. • Check for correct wiring and good connections. • If display is blank or displays “bAt Lo,” install fresh batteries. • Allow time for the furnace to heat up and the fan to come on before checking for heat at the register. • If temperature setting is higher than current room temperature and SYSTEM ON arrow is displayed, thermostat is operating correctly. Contact heating contractor for assistance. |
Cooling does not come on | • Check that the System switch is set to COOL. • Check the system fuse or circuit breaker and replace or reset if necessary. • Check for correct wiring and good connections. • If display is blank or says “bAt Lo,” install fresh batteries. • The thermostat has a built-in time delay on cooling. Allow 5-10 minutes after changing setting before air conditioner starts. • If temperature setting is lower than room temperature and SYSTEM ON arrow is displayed, thermostat is operating correctly. Contact ac contractor. |
The house is too warm or too cool | • Press RUN PROGRAM to check the current temperature setting. • If desired, change the temperature setting. |
Furnace cycles too often or system cycle length is too short or too long | • Adjust the screws on the back of the thermostat. |
The thermostat current setting does not match the display temperature to within plus or minus 1° | • Plug the wiring hole in the wall behind the mounting plate with insulation to prevent drafts that might adversely affect thermostat operation. • Be aware that it is normal for the current setting and the displayed room temperature to differ on occasion. • During recovery from setback or setup, setting and displayed room temperatures can differ for up to 30 minutes after recovery period. |
Visit us on the Web at www.honeywell.com/yourhome or call Honeywell Customer Care at 1-800-468-1502. Before you call, please have the following information available:
Honeywell warrants this product, excluding battery, to be free from defects in workmanship or materials, under normal use and service, for a period of one (1) year from the date of purchase by the consumer. If, at any time during the warranty period, the product is defective or malfunctions, Honeywell shall repair or replace it (at Honeywell’s option) within a reasonable period of time.If the product is defective,
This warranty does not cover removal or reinstallation costs. This warranty shall not apply if it is shown by Honeywell that the defect or malfunction was caused by damage that occurred while the product was in the possession of a consumer.
Honeywell’s sole responsibility shall be to repair or replace the product within the terms stated above. HONEYWELL SHALL NOT BE LIABLE FOR ANY LOSS OR DAMAGE OF ANY KIND, INCLUDING ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES RESULTING, DIRECTLY OR INDIRECTLY, FROM ANY BREACH OF ANY WARRANTY, EXPRESS OR IMPLIED, OR ANY OTHER FAILURE OF THIS PRODUCT. Some states do not allow the exclusion or limitation of incidental or consequential damages, so this limitation may not apply to you.
THIS WARRANTY IS THE ONLY EXPRESS WARRANTY HONEYWELL MAKES ON THIS PRODUCT. THE DURATION OF ANY IMPLIED WARRANTIES, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, IS HEREBY LIMITED TO THE ONE-YEAR DURATION OF THIS WARRANTY. Some states do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply to you.
This warranty gives you specific legal rights, and you may have other rights which vary from state to state.
If you have any questions concerning this warranty, please write Honeywell Customer Relations Center, 1985 Douglas Dr. N., Golden Valley, MN 55422-3992, or call 1-800-468-1502. In Canada, write Retail Products ON15 Honeywell Limited/Honeywell Limitée, 35 Dynamic Drive, Scarborough, Ontario M1V 4Z9.
Automation and Control Solutions
Download manual: Honeywell Home CT2800 Programmable Thermostat INSTALLATION AND PROGRAMMING INSTRUCTIONS
Honeywell Home CT2800 Programmable Thermostat INSTALLATION AND PROGRAMMING INSTRUCTIONS
Johnson Controls T7000e LCD Digital Thermostat Johnson Controls T7000e LCD Digital Thermostat Installation Guide
Honeywell T8635L Microelectronic Communicating Programmable Thermostat Honeywell T8635L Microelectronic Communicating Programmable Thermostat USER’s GUIDE
Hetta HS01RF WIRELESS THERMOSTAT Kit PAIRING INSTRUCTIONS Insert batteries into the Thermostat. Ensure that the…
HEAT-MAT NGT-567-0010 Underfloor Heating Thermostat Menu Introduction The NGT thermostat can switch your underfloor heating…
Honeywell RLV450 PROGRAMMABLE THERMOSTAT READ BEFORE INSTALLING DESCRIPTION * LP appears only for the first…
Honeywell RLV431 Programmable Thermostat Description The RLV431 thermostat can be used to control an electric…