Owner's Manual
Page 1
... proper disposal of your system. Programmable Heat and/or Cool Low Voltage (20 to make sure this thermostat that contains mercury in a sealed tube, do not place your old control in your home, keeping you with your new thermostat! If not, return it properly. Dispose of Honeywell engineering produced this thermostat is replacing a control that can provide you comfortable while saving energy when programmed according to the retailer. ❑...
... proper disposal of your system. Programmable Heat and/or Cool Low Voltage (20 to make sure this thermostat that contains mercury in a sealed tube, do not place your old control in your home, keeping you with your new thermostat! If not, return it properly. Dispose of Honeywell engineering produced this thermostat is replacing a control that can provide you comfortable while saving energy when programmed according to the retailer. ❑...
Owner's Manual
Page 2
.... CT3451 PROGRAMMABLE THERMOSTAT 2 REMOVE OLD THERMOSTAT ❑ Test to be sure your heating and air conditioning systems (where applicable) are six or more wires connected to the thermostat (excluding clock wires attached to terminals), you want information about which programmable thermostats work with your system, visit our Web site at www.honeywell.com/yourhome or call the customer information line at furnace or main breaker/ fuse box before beginning installation...
.... CT3451 PROGRAMMABLE THERMOSTAT 2 REMOVE OLD THERMOSTAT ❑ Test to be sure your heating and air conditioning systems (where applicable) are six or more wires connected to the thermostat (excluding clock wires attached to terminals), you want information about which programmable thermostats work with your system, visit our Web site at www.honeywell.com/yourhome or call the customer information line at furnace or main breaker/ fuse box before beginning installation...
Owner's Manual
Page 3
... to wall. ❑ Remove the wallplate from adversely affecting thermostat operation. Fig. 4. Tighten the terminals. M12202A Fig. 3. holes in . Loosely insert the mounting screws into the drilled holes until flush with local electrical codes and ordinances. the thermostat functions correctly even when not level. Connecting wiring. Mounting wallplate to Fig. 4. Level the wallplate for typical system wiring diagrams. 3 69-1620-1 For firmer wall material...
... to wall. ❑ Remove the wallplate from adversely affecting thermostat operation. Fig. 4. Tighten the terminals. M12202A Fig. 3. holes in . Loosely insert the mounting screws into the drilled holes until flush with local electrical codes and ordinances. the thermostat functions correctly even when not level. Connecting wiring. Mounting wallplate to Fig. 4. Level the wallplate for typical system wiring diagrams. 3 69-1620-1 For firmer wall material...
Owner's Manual
Page 4
... CHANGEOVER VALVE ON SINGLE-STAGE HEAT PUMP SYSTEMS. M20511 Fig. 9. M20537 Fig. 8. CT3451 PROGRAMMABLE THERMOSTAT THERMOSTAT G Rc R 3 1 L1 (HOT) L2 W Y HEAT RELAY FAN RELAY COMPRESSOR CONTACTOR B O 2 COOL DAMPER 2 HEAT DAMPER TRANSFORMER 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 CAN BE USED FOR CHANGEOVER VALVE ON SINGLE-STAGE HEAT PUMP SYSTEMS. 3 JUMPER R TO Rc. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. Typical heat-cool system hookup with 3-wire, cool-only system.
... CHANGEOVER VALVE ON SINGLE-STAGE HEAT PUMP SYSTEMS. M20511 Fig. 9. M20537 Fig. 8. CT3451 PROGRAMMABLE THERMOSTAT THERMOSTAT G Rc R 3 1 L1 (HOT) L2 W Y HEAT RELAY FAN RELAY COMPRESSOR CONTACTOR B O 2 COOL DAMPER 2 HEAT DAMPER TRANSFORMER 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 CAN BE USED FOR CHANGEOVER VALVE ON SINGLE-STAGE HEAT PUMP SYSTEMS. 3 JUMPER R TO Rc. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. Typical heat-cool system hookup with 3-wire, cool-only system.
Owner's Manual
Page 5
...-stage heat pump system hookup. 5 ADJUST FAN OPERATION SWITCH The thermostat fan operation switch, labeled fuel switch in Fig. 11, is connected.See Fig. 11. E F FAN OPERATION (FUEL) SWITCH M20530 Fig. 11. T8002 THERMOSTAT G Rc FAN RELAY R 3 W 4B Y 2 O 1 L1 (HOT) L2 COMPRESSOR CONTACTOR COOL CHANGEOVER VALVE HEAT CHANGEOVER VALVE TRANSFORMER 1 POWER SUPPLY. The E setting allows the fan to turn on immediately with the heating equipment in the F (gas/oil fuel) position. M20513 Fig. 12. PM TUE AuFtoANOn Hold...
...-stage heat pump system hookup. 5 ADJUST FAN OPERATION SWITCH The thermostat fan operation switch, labeled fuel switch in Fig. 11, is connected.See Fig. 11. E F FAN OPERATION (FUEL) SWITCH M20530 Fig. 11. T8002 THERMOSTAT G Rc FAN RELAY R 3 W 4B Y 2 O 1 L1 (HOT) L2 COMPRESSOR CONTACTOR COOL CHANGEOVER VALVE HEAT CHANGEOVER VALVE TRANSFORMER 1 POWER SUPPLY. The E setting allows the fan to turn on immediately with the heating equipment in the F (gas/oil fuel) position. M20513 Fig. 12. PM TUE AuFtoANOn Hold...
Owner's Manual
Page 6
... Your Honeywell thermostat comes preset to choose either the Fahrenheit (°F) or Celsius (°C) display. M12584A ❑ Setting °C or °F. - Setting °F/°C Indication, Heat Cycle Rate, Heating/Cooling Temperature Control The following instructions provide information to change the heat cycle rate, press the ▼ key until End displays. M14691 - CT3451 PROGRAMMABLE THERMOSTAT AA BATTERIES (3) PM TUE AuFtoANOn Hold Select CoolSOYfSf THEeMat - Press the ▲ key to display the three-digit software revision code. (Information displayed varies...
... Your Honeywell thermostat comes preset to choose either the Fahrenheit (°F) or Celsius (°C) display. M12584A ❑ Setting °C or °F. - Setting °F/°C Indication, Heat Cycle Rate, Heating/Cooling Temperature Control The following instructions provide information to change the heat cycle rate, press the ▼ key until End displays. M14691 - CT3451 PROGRAMMABLE THERMOSTAT AA BATTERIES (3) PM TUE AuFtoANOn Hold Select CoolSOYfSf THEeMat - Press the ▲ key to display the three-digit software revision code. (Information displayed varies...
Owner's Manual
Page 7
... day. Wake a. Press the ▲ key. CT3451 PROGRAMMABLE THERMOSTAT NOTE: The heating and cooling program times are sleeping. Return is the time period when you want to exit the programming mode. A flame (heating) or a snowflake (cooling) appears in the morning. - A typical example is shown, but CC varies by model. (This information is the time period you want the house at a comfortable temperature when you come home during the day. Heating Cycle Rate. To set an energysaving temperature...
... day. Wake a. Press the ▲ key. CT3451 PROGRAMMABLE THERMOSTAT NOTE: The heating and cooling program times are sleeping. Return is the time period when you want to exit the programming mode. A flame (heating) or a snowflake (cooling) appears in the morning. - A typical example is shown, but CC varies by model. (This information is the time period you want the house at a comfortable temperature when you come home during the day. Heating Cycle Rate. To set an energysaving temperature...
Owner's Manual
Page 8
... set Return time. Press Select. Press ▼ or ▲ key to set Wake time. SET SET M18566 b. Return a. Press ▼ or ▲ key to set Leave temperature. Press Select. Press ▼ or ▲ key to set Return temperature. Sleep a. M20561 3. Leave. Press Select. SET M20560 b. Wake a. Press ▼ or ▲ key to set Wake temperature. Press ▼ or ▲ key to set Sleep temperature. M20558 b. SET SET M20563 M12631C 69-1620-1 8 CT3451 PROGRAMMABLE THERMOSTAT SET M12625C 2. a. SET...
... set Return time. Press Select. Press ▼ or ▲ key to set Wake time. SET SET M18566 b. Return a. Press ▼ or ▲ key to set Leave temperature. Press Select. Press ▼ or ▲ key to set Return temperature. Sleep a. M20561 3. Leave. Press Select. SET M20560 b. Wake a. Press ▼ or ▲ key to set Wake temperature. Press ▼ or ▲ key to set Sleep temperature. M20558 b. SET SET M20563 M12631C 69-1620-1 8 CT3451 PROGRAMMABLE THERMOSTAT SET M12625C 2. a. SET...
Owner's Manual
Page 9
...set a temporary temperature setting. After approximately five seconds, the thermostat displays the current time and room temperature. In cooling, the fan starts and stops with the heating equipment. ❑ Slide the Fan switch on most homes. Press Select. SET M12641A M20565 5. To cancel, press Hold twice. Fan Switch ❑ The Fan switch settings are displayed continuously. SET M20564 b. When Hold is active, the letters Hld are : On: The fan runs continuously. Programming is displayed. CT3451 PROGRAMMABLE THERMOSTAT Setting Indefinite Temperature Hold The Hold...
...set a temporary temperature setting. After approximately five seconds, the thermostat displays the current time and room temperature. In cooling, the fan starts and stops with the heating equipment. ❑ Slide the Fan switch on most homes. Press Select. SET M12641A M20565 5. To cancel, press Hold twice. Fan Switch ❑ The Fan switch settings are displayed continuously. SET M20564 b. When Hold is active, the letters Hld are : On: The fan runs continuously. Programming is displayed. CT3451 PROGRAMMABLE THERMOSTAT Setting Indefinite Temperature Hold The Hold...
Owner's Manual
Page 10
... temperature; A flashing snowflake is triggered. The fan should shut down . Refer to the desired system setting. Press the ▲ key to lower the temperature setting below 50°F (10°C). CT3451 PROGRAMMABLE THERMOSTAT System Switch ❑ The System switch settings control thermostat operation as follows: Cool: The thermostat controls the cooling system. Off: Both heating and cooling are off -time of an outdoor temperature can cause compressor damage. The minimum off-timer is triggered when the compressor turns...
... temperature; A flashing snowflake is triggered. The fan should shut down . Refer to the desired system setting. Press the ▲ key to lower the temperature setting below 50°F (10°C). CT3451 PROGRAMMABLE THERMOSTAT System Switch ❑ The System switch settings control thermostat operation as follows: Cool: The thermostat controls the cooling system. Off: Both heating and cooling are off -time of an outdoor temperature can cause compressor damage. The minimum off-timer is triggered when the compressor turns...
Owner's Manual
Page 11
... "Cooling does not come on indicator ( = heat; = cool) is lighted, but no hot or cool air coming from the registers, refer to 37°C). Your thermostat has reached the temperature limit. Make sure the current day and time are fresh and installed correctly. System on before the air conditioner starts. • If the temperature setting is lower than the current room temperature and the snowflake is displaying, the thermostat is operating correctly. If ... Adjust heat cycle...
... "Cooling does not come on indicator ( = heat; = cool) is lighted, but no hot or cool air coming from the registers, refer to 37°C). Your thermostat has reached the temperature limit. Make sure the current day and time are fresh and installed correctly. System on before the air conditioner starts. • If the temperature setting is lower than the current room temperature and the snowflake is displaying, the thermostat is operating correctly. If ... Adjust heat cycle...
Owner's Manual
Page 12
..., so this product, excluding battery, to be to repair or replace the product within a reasonable period of the malfunction, and mail it, postage prepaid, to you . www.honeywell.com/yourhome This warranty gives you specific legal rights, and you may not apply to state. CT3451 PROGRAMMABLE THERMOSTAT PERCENT OF HEATING COSTS YOU CAN SAVE SAVINGS FOR ONCE-A-DAY 10°F (5°...
..., so this product, excluding battery, to be to repair or replace the product within a reasonable period of the malfunction, and mail it, postage prepaid, to you . www.honeywell.com/yourhome This warranty gives you specific legal rights, and you may not apply to state. CT3451 PROGRAMMABLE THERMOSTAT PERCENT OF HEATING COSTS YOU CAN SAVE SAVINGS FOR ONCE-A-DAY 10°F (5°...