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Honeywell CT3550
PROGRAMMABLE THERMOSTAT
OWNER’S GUIDE
Weekday, Saturday and Sunday
Programmable Heat and/or Cool
Low Voltage (20 to 30 Vac) Thermostat and Wallplate
Model CT3550
Para pedir estas instrucciones en español, llame al 1-800-468-1502.
Pour obtenir ce ode demploi en français, composer le 1-800-468-1502.
Table of Contents
Step 1. Prepare for Installation .................................................................................................................................. 5
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Total comfort temperature management with Smart Response™ Technology. Congratulations! You made a smart choice by purchasing your new Honeywell thermostat the smart thermostat that; Keeps you comfortable by automatically calculating exactly when the furnace or air conditioning should go on to have the house at the desired comfort temperature by the time you wake up or return home. Saves the maximum amount of energy and money by automatically remembering to adjust the temperature when you l
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DIGITAL DISPLAY RAISES TEMPERATURE SETTING SET CURRENT LOWERS DAY/TIME TEMPERATURE SETTING SETS CURRENT TIME AND DAY DISPLAYS CURRENT HEAT/COOL TEMPERATURE SETTING RUN PROGRAM RETURNS THERMOSTAT PROGRAM PERIODS Time Set Program WAKE/LEAVE/RETURN/SLEEP: TO NORMAL Run Set Current Wake Leave Return Sleep Program Day/Time OPERATING MODE ENTERS PROGRAMMING MODE Heat/Cool Hold Temp Day Settings HOLD TEMP SETS A HOLD HEAT/COOL SETTING Fan System TEMPERATURE SWITCHES BETWEEN SETTING AND HEAT SE
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DISPLAYS EITHER CURRENT SHOWS THERMOSTAT IS IN TIME OF DAY OR PROGRAM TIMES THE SET DAY/TIME MODE SHOWS WHEN THERMOSTAT IS IN THE SHOWS TEMPERATURE SETTING PROGRAMMING MODE CHANGED FOR THIS PROGRAM PERIOD SHOWS VACATION SHOWS THE TEMPERATURE HOLD DURATION DISPLAYED IS THE CURRENT Temporary Setting Set Program Set Day/Time SET TEMPERATURE Hold for SHOWS CURRENT AM DAY OR DAYS BEING Em Ht Room SHOWS THE TEMPERATURE PROGRAMMED DISPLAYED IS THE CURRENT Humid Aux Ht ROOM TEMPERATURE MonTueWed
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STEP 1. PREPARE FOR INSTALLATION ❑ Check Table 1, the compatibility chart, to make sure the thermostat is compatible with your system. If your system is not compatible, call Honeywell Customer Relations Center, toll-free, 1-800-468-1502. Table 1. Compatibility Chart. System Type Compatibility with CT3550 Gas — Standing Pilot Yes Gas — Electronic Ignition Yes a Gas-fired Boilers Yes Gas — 750 Millivolt Heat Yes a Oil-Fired Boilers Yes Oil-Fired Furnace Yes Electric Furnace Yes Electric Air Cond
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STEP 2. REMOVE OLD THERMOSTAT ❑ Test your heating and cooling systems to make sure they work properly. If either system does not work, contact your local heating/air-conditioning dealer. To avoid compressor damage, do not operate the cooling system when outdoor temperature is below 50°F (10°C). ❑ Turn off power to the system at the furnace or the fuse/circuit breaker panel. ❑ Carefully unpack your new thermostat and wallplate. Save package of screws, instructions, and receipt. ❑ Remove the cov
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Replacing a Thermostat that has Three Wires If you have three wires for a heating only system and can operate the fan using the fan ON switch this thermostat works with your system. However, some hot water (zoned) heating systems also have three wires. Your thermostat will work only if you install an isolating relay on these systems. For details, call your local heating and/or cooling contractor. STEP 3. MOUNT THERMOSTAT WALLPLATE ❑ Separate the wallplate from the thermostat by placing your t
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G Y W R STEP 4. WIRE WALLPLATE TERMINALS IMPORTANT All wiring must comply with local codes and ordinances. If unsure about household wiring procedures, call your local heating/air-conditioning contractor. Refer to the labels you placed on the wires when you removed the old thermostat (see illustration). ❑ Match the letter of your old thermostat wire with the corresponding terminal letter on your new thermostat. Refer to Table 2. ❑ Remove the factory-installed jumper connecting terminals R an
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Table 2. Terminal Designations on Old and New Thermostats Terminal on Old Thermostat Connect To Description a R Power R, RH , 4, V a Rc Power for cooling Rc, R W, W , H W Heat 1 Y, Y , M Y Cooling 1 G, F G Fan O O Changeover in cool. (Single stage heat pump only). b b Changeover in heat. (Single stage heat pump only). B B c c b Do not connect. Transformer common C , X , B W , H Do not continue installation. Second stage heat. 2 2 Call 1-800-468-1502. Y Second stage cool. 2 a If both RH and R ter
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90 60 80 70 ❑ If the thermostat is already mounted on the wall, remove the thermostat by placing your thumb between the thermostat and wallplate and pulling the thermostat up and away as shown. When the batteries are running low, a REPL BAT message flashes for one to two months before the batteries run out completely. Replace the batteries as soon as possible once the message flashes. IMPORTANT Although the thermostat has a low battery indicator, replace the batteries once per year to preve
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STEP 7. CUSTOMIZE YOUR THERMOSTAT Your Honeywell CT3550 thermostat comes preset to the most commonly used settings. The settings are: — Gas or oil forced air furnace. — Smart Response technology on. — Temperature °F. — 12-hour clock format. You can change any or all of these settings. IMPORTANT Always press the keys with your fingertip or a similar blunt tool. Sharp instruments like pens and pencil points can damage the keyboard. ❑ Press and hold down , , and , simultaneously until the screen s
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To change your system type: ❑ Press until display shows your furnace or boiler type. Run Program ❑ Press Time to move to next feature or to return to main display. Smart Response™ Technology (Feature Number 13) Smart Response technology options are: — 0 = Smart Response technology on (preset). — 1 = Smart Response technology off. M13343 To turn Smart Response technology on or off: ❑Press once. Run Program ❑ Press Time to move to next feature or to return to main display. NOTE: See Smart Re
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Factory Set Function (Feature Number 37) Do not change this setting. STEP 8. SET THE CLOCK M13346 Set Current Day and Time NOTE: On initial power-up, the screen flashes 1:00 pm until you press a key. Set Current Day/Time ❑Press . Day ❑ Press until screen shows current day. Set Current Day/Time ❑ Press time or until screen shows current time. (Tapping the will advance the time in one hour increments). Run Program ❑Press . STEP 9. PROGRAMMING The keyboard is located behind the thermostat cove
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Table 3 can be helpful when planning your schedule of time and temperature settings. The thermostat default settings are shown in parentheses ( ). Table 3. Personal Programming Table. Period Default Setting Weekday (Mon-Fri) Saturday (Sat) Sunday (Sun) Wake Time (6:00AM) a Heat (70°F/21°C) b Cool (78°F/25.5°C) Leave Time (8:00AM) a Heat (62°F/16.5°C) b Cool (85°F/29.5°C) Return Time (6:00PM) a Heat (70°F/21°C) b Cool (78°F/25.5°C) Sleep Time (10:00PM) a Heat (62°F/16.5°C) b Cool (82°F/28°C) a
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❑ Press or until the desired wake temperature displays. The setpoint temperature range is 40°F to 90°F (4.5°C to 32°C) for heating and 45°F to 99°F (7°C to 37°C) for cooling. Heat/Cool Settings ❑ Press to switch between setpoints. NOTE: Program times are the same for heating and cooling. ❑ Press or until the display shows the desired temperature setpoint. Fan ❑ Press until the fan is at the desired setting (On or Auto). NOTE: Setting Fan to On runs the system fan continuously in the progra
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STEP 10. OPERATING YOUR THERMOSTAT Change Temperature Setting Until the Next Program Period (Temporary Change) ❑ Press or until the screen shows the desired temperature setting. NOTE: The temporary temperature setting is displayed for about 3 seconds and then the room temperature is dis- played. Temporary appears in the display. The setting cancels when the next program period starts or when Run Program you press . Change Temperature Setting Indefinitely (Hold) System ❑Press until “Heat” or
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STEP 11. SET THE FAN AND SYSTEM KEY Set the Fan Key Fan On: The fan runs continuously. Use for improved air circulation or more efficient central air cleaning. (In a heat only system, the fan runs continuously only if the fan relay is connected to the G thermostat terminal). Fan Press until display shows On. Fan Auto: Normal setting for most homes. The equipment controls the fan operation. Fan Press until display shows Auto. NOTE: If you set the fan to On during normal operation, the fan reve
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If You Have a Problem Table 4. Solution Guide. If... Then… Display does not appear. Make sure the batteries are installed correctly. Make sure the thermostat is mounted and latched on the wallplate. Mount and latch the thermostat on the wallplate if it is not. Temperature settings will not change Make sure the temperature setpoints are: (example; cannot set the heating 40 to 90°F (4.5 to 32°C) for heating. higher or the cooling lower). 45 to 99°F (7 to 37°C) for cooling. Heating does not
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Table 4. Solution Guide. If... Then… Temperature change occurs at the 1. Check the program times for the period in question. wrong times. 2. Make sure the AM and PM settings are correct. 3. Make sure the current time and day settings are correct. 4. Reprogram any incorrect settings. NOTE: If your thermostat is set for Smart Response control, the start times occur before your programmed comfort periods. Toll-Free Customer Assistance Please read and follow the provided instructions for this ther
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SMART RESPONSE™ TECHNOLOGY Your CT3550 is actually a small computer. The Smart Response technology calculates the correct time of day to turn on your heating or cooling system. Smart Response technology considers the following information. Air temperature. Wall temperature. The time of day when you want the comfort temperature established. System Operating When the thermostat activates Smart in Comfort Mode Response technology, the thermostat AM Room 68°F Mon Wake displays In Recovery,
