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 .................................................................................................................................. Step 2.
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.
DIGITAL DISPLAY RAISES TEMPERATURE SETTING SET CURRENT DAY/TIME LOWERS TEMPERATURE SETTING SETS CURRENT TIME AND DAY DISPLAYS CURRENT HEAT/COOL TEMPERATURE SETTING RUN PROGRAM RETURNS THERMOSTAT TO NORMAL OPERATING MODE HOLD TEMP Time Run Program Hold Temp SETS A HOLD TEMPERATURE SETTING AND ACTIVATES VACATION HOLD FEATURE Set Current Day/Time PROGRAM PERIODS Set Program Leave Wake Return Sleep WAKE/LEAVE/RETURN/SLEEP: ENTERS PROGRAMMING MODE Heat/Cool Settings Day HEAT/COOL SETTING Fan
DISPLAYS EITHER CURRENT TIME OF DAY OR PROGRAM TIMES SHOWS THERMOSTAT IS IN THE SET DAY/TIME MODE SHOWS WHEN THERMOSTAT IS IN THE PROGRAMMING MODE SHOWS TEMPERATURE SETTING CHANGED FOR THIS PROGRAM PERIOD SHOWS VACATION HOLD DURATION SHOWS CURRENT DAY OR DAYS BEING PROGRAMMED SHOWS CURRENT PROGRAM PERIOD OR PERIOD BEING PROGRAMMED Set Program Set Day/Time Temporary Setting Hold for AM Em Ht Room Humid Aux Ht Outdoor MonTueWedThuFriSatSun Days WakeLeaveReturnSleep In Recovery Filter Repl Batt Fan Syst
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.
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.
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.
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. W Y FOR WRAPAROUND INSERTION STRIP 7/16 IN. (11 MM). R G 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.
Table 2. Terminal Designations on Old and New Thermostats Terminal on Old Thermostat Connect To Description R, RH , 4, V R Power Rc, Ra Rc Power for cooling W, W1, H W Heat Y, Y1, M Y Cooling a G, F G Fan O O Changeover in cool. (Single stage heat pump only). Bb Changeover in heat. (Single stage heat pump only). C,X,B Do not connect. Transformer common W2, H2 Do not continue installation. Call 1-800-468-1502. Bb c Y2 c b Second stage heat. Second stage cool.
❑ 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.
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 shows.
To change your system type: ❑ Press until display shows your furnace or boiler type. ❑ Press Time to move to next feature or Run Program 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. ❑ Press Time NOTE: to move to next feature or Run Program to return to main display.
Factory Set Function (Feature Number 37) Do not change this setting. STEP 8. SET THE CLOCK M13346 Set Current Day and Time NOTE: ❑ Press ❑ Press On initial power-up, the screen flashes 1:00 pm until you press a key. Set Current Day/Time . Day until screen shows current day. ❑ Press time increments). ❑ Press Run Program or until screen shows current time. (Tapping the Set Current Day/Time will advance the time in one hour . STEP 9.
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 Wake Weekday (Mon-Fri) Saturday (Sat) Time (6:00AM) Heata (70°F/21°C) Coolb (78°F/25.5°C) Leave Time (8:00AM) Heata (62°F/16.5°C) Coolb (85°F/29.5°C) Return Time (6:00PM) Heata (70°F/21°C) Coolb (78°F/25.5°C) Sleep Time (10:00PM) Heata (62°F/16.
❑ 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. ❑ Press NOTE: Heat/Cool Settings Program times are the same for heating and cooling. ❑ Press ❑ Press NOTE: ❑ Press to switch between setpoints. or until the display shows the desired temperature setpoint. Fan until the fan is at the desired setting (On or Auto).
STEP 10. OPERATING YOUR THERMOSTAT Change Temperature Setting Until the Next Program Period (Temporary Change) ❑ Press NOTE: or until the screen shows the desired temperature setting. The temporary temperature setting is displayed for about 3 seconds and then the room temperature is displayed. Temporary appears in the display. The setting cancels when the next program period starts or when you press Run Program .
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). Press Fan until display shows On. Fan Auto: Normal setting for most homes. The equipment controls the fan operation. Press NOTE: Fan until display shows Auto.
If You Have a Problem Table 4. Solution Guide. If... Display does not appear. Then… • • Temperature settings will not change • (example; cannot set the heating higher or the cooling lower). Heating does not come on. • • • • • Cooling does not come on. • • • • • = System on indicator ( = heat, cool) is lit, but no warm or cool air is coming from the registers. Make sure the batteries are installed correctly. Make sure the thermostat is mounted and latched on the wallplate.
Table 4. Solution Guide. If... Temperature change occurs at the wrong times. Then… 1. Check the program times for the period in question. 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 thermostat.
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.
WIRING DIAGRAMS 4-WIRE HEAT/COOL (JUMPER INTACT) 2-WIRE HEAT-ONLY (JUMPER INTACT) THERMOSTAT B THERMOSTAT B RC O W Y RC O W Y R R G G HEATING RELAY OR VALVE COIL HEATING RELAY OR VALVE COIL COOLING CONTACTOR COIL FAN RELAY 1 1 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
5-WIRE HEAT/COOL WITH DAMPER (JUMPER INTACT) 5-WIRE HEAT/COOL (JUMPER REMOVED) THERMOSTAT B THERMOSTAT B RC O W Y RC O W Y HEATING RELAY OR VALVE COIL 1 FAN RELAY G R G R HEAT DAMPER COOLING CONTACTOR COIL 1 HEAT RELAY COOL DAMPER 1 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD M10619 PROTECTION AS REQUIRED. COMPRESSOR CONTACTOR FAN RELAY 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
Limited One-Year Warranty Honeywell warrants this product, excluding battery, to be free from defects in the 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 Honeywells option) within a reasonable period of time.
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