Daikin 910121748 Programmable Thermostat

Specifications

Package Contents & Tools Required

Package includes: 910121748 thermostat on base, thermostat cover, wiring labels, screws and wall anchors, Installation, Operation and Application Guide.

Tools required for installation: Drill with 3/16” bit, hammer, screwdriver.

Important Safety Information

WARNING!: Always turn off power at the main power supply before installing, cleaning, or removing thermostat.

• This thermostat is for 24 VAC applications only; do not use on voltages over 30 VAC.
• All wiring must conform to local and national electrical and building codes.
• Do not use air conditioning when the outdoor temperature is below 50 degrees; this can damage your A/C system and cause personal injuries.
• Use this thermostat only as described in this manual.

Installation

To Remove Existing Thermostat

ELECTRICAL SHOCK HAZARD – Turn off power at the main service panel by removing the fuse or switching the appropriate circuit breaker to the OFF position before removing the existing thermostat.

1. Turn off power to the heating and cooling system.
2. Remove cover of old thermostat to expose wires.
3. Label existing wires with enclosed wire labels before removing wires.
4. Remove wires from wire terminals.
5. Remove existing thermostat base from wall.
6. Refer to the following section for installation instructions.

To Install Thermostat

ELECTRICAL SHOCK HAZARD – Turn off power at the main service panel by removing the fuse or switching the appropriate circuit breaker to the OFF position before removing the existing thermostat.

IMPORTANT: Thermostat installation must conform to local and national building and electrical codes and ordinances.

Note: Mount the thermostat about five feet above the floor. Do not mount on an outside wall, in direct sunlight, behind a door, or in an area affected by a vent or duct.

1. Turn off power to the heating and cooling system.
2. To remove cover, pull gently at the seam at the top.
3. Place thermostat base against the wall where you plan to mount it, ensuring wires feed through the wire opening.
4. Mark the placement of the mounting holes.
5. Set thermostat base and cover away from working area.
6. Using a 3/16” drill bit, drill holes in the marked places.
7. Use a hammer to tap supplied anchors into mounting holes.
8. Align thermostat base with mounting holes and feed control wires through the thermal intrusion barrier and into the wire opening.
9. Use supplied screws to mount thermostat base to wall.
10. Insert stripped, labeled wires into matching wire terminals.
11. CAUTION!: Be sure exposed portions of wires do not touch other wires.
12. Gently tug wire to ensure proper connection. Double-check that each wire is connected to the proper terminal.
13. Turn on power to the system at the main service panel.
14. Configure thermostat to match your system type.
15. Replace cover by snapping it in place.
16. Test thermostat operation as described in “Testing the Thermostat”.

Icon Descriptions

• Cooling operation icon: ❄️
• Fan operation icon: ?
• Heating operation icon: ?
• Room temperature offset activated: ?
• Display shows: 1ST Cool, 2ND Cool, 1ST Heat, 2ND Heat
• Terminal mapping: Heat/Cool Y1, Y1/Y2, W1, W1/W2

Wiring Diagrams

The thermostat has terminals: S1, S2, R, C, W1, Y1, W2, Y2, G, A, O.

The main control board has terminals TB1 and TB2.

Wiring Connections (Example):

• Thermostat Terminal to Control Board Terminal:
• S1 to S1
• S2 to S2
• R to R
• C to C
• Y1 to Y1
• Y2 to Y2
• W1 to W1
• W2 to W2
• G to G
• A to A
• O to O/B

Note: Specific wiring depends on system configuration. Refer to detailed diagrams if available.

Configuration Mode

The 910121748 thermostat is configurable for all systems. The configuration directly affects the outputs. Use the output chart to correctly configure and wire the thermostat to your system.

To Enter Configuration Mode:

1. Verify the 910121748 is in the OFF mode (Press SYS [left] button until OFF mode displays).
2. Remove the thermostat cover by gently pulling near a top corner.
3. Press the CONFIG button for 1 second while in OFF mode.
4. To exit configuration mode, press the CONFIG switch for 1 second.

Navigation:

• Use the UP or DOWN buttons to change settings.
• Press the RIGHT button to advance to the next screen.
• Press the LEFT button to return to the previous screen.

Configuration Mode Settings:

1. Temperature Scale: Choose Fahrenheit (F) or Celsius (C).
2. 1st Stage Temperature Differential: Set the degrees between setpoint and turn-on temperature (1°F to 5°F / 0.5°C to 2.5°C).
3. 2nd Stage Temperature Differential: Set degrees between stage 1 turn-on and stage 2 turn-on (1°F to 5°F / 0.5°C to 2.5°C).
4. Staged Off Outputs: Select if heating/cooling outputs are staged off independently (1) or simultaneously (0).
5. Minimum Deadband: Set minimum separation between heat and cool setpoints in Auto Changeover Mode (1°F to 9°F / 1°C to 5°C).
6. Maximum Heat Setpoint: Control maximum heat set temperature (55°F to 90°F / 13°C to 32°C).
7. Minimum Cool Setpoint: Control minimum cool set temperature (55°F to 90°F / 13°C to 32°C).
8. Room Temperature Offset: Calibrate displayed room temperature (+9°F to -9°F / +4.5°C to -4.5°C). Displays ? when set.
9. Temperature Sensor:
   1. Only on-board sensor.
   2. Only remote sensor.
   3. Average of on-board and remote sensors.
   4. On-board until NITE period, then remote sensor.

   Note: If no remote sensor, option 1 must be selected.

Press the CONFIG button for two seconds to exit configuration.

Mode of Operation

The 910121748 is a programmable, manual or auto changeover, 2-stage heat, 2-stage cool thermostat. An outdoor sensor can be used to monitor outdoor temperature.

The thermostat activates heating when room temperature is below the set heat temperature (by differential). It stops outputting when the call for heat is satisfied.

When room temperature is greater than the set cool temperature (by differential), cooling is activated. It stops outputting when the call for cooling is satisfied.

The thermostat has five possible operating modes: OFF, Heat, Cool, Heat & Cool, and Program mode.

• OFF Mode: Thermostat does not turn on heating or cooling devices.
• Heat Mode: Controls the heating system. ? icon appears when heating.
• Cool Mode: Controls the cooling system. ❄️ icon appears when cooling.
• Heat & Cool Mode (Auto Changeover): Controls both systems, automatically changing over. Time display alternates with set temperature every 10 seconds.
• Program Mode: Thermostat is controlled by the set program schedule. Can function with Heat, Cool, or Heat & Cool. Program schedule can be overridden by changing set temperature (temporary 2-hour hold). Press PROG button twice to return to program schedule.

Programmable Fan: Recirculates air in Program mode, activated during program schedule setup.

Night Set-back Override: Press UP and DOWN buttons simultaneously for 2 seconds. Outputs from "O" terminal for 5 seconds. "Or" shows on display.

Reset Unit: Press UP and DOWN buttons simultaneously for 5 seconds. Outputs from "O" terminal for 10 seconds. "rS" shows on display.

Button Functions

• UP: Increase time, set temperatures, adjust configuration settings.
• DOWN: Decrease time, set temperatures, adjust configuration settings.
• SYS (left): Change modes (OFF, HEAT, COOL, AUTO changeover).
• FAN (right): Turn indoor fan ON/OFF.
• PROG (SYS and FAN pressed simultaneously): Change from program operation to manual operation.
• DOWN and SYS (pressed simultaneously): Display outdoor remote temperature if remote sensor is connected.
• UP and DOWN (pressed simultaneously): Override night set back or reset the unit.

Remote Sensor Installation (Optional)

Terminals S1 and S2 can be used for an indoor remote sensor to read temperature in a different location.

Remote sensor P/N: 910116773.

Installation Steps:

1. Remove cover from remote sensor housing.
2. Select an appropriate location for mounting.
3. Mount remote sensor unit using provided hardware.
4. Install two-strand shielded wire between sensor and thermostat. Shielded wire is recommended. Do not run sensor wire in conduit with other wires.
5. Wire 1: Thermostat S1 terminal to Remote Sensor S1 terminal.
6. Wire 2: Thermostat S2 terminal to Remote Sensor S2 terminal.
7. Connect the shielding of the wire to the S2 terminal on the thermostat.
8. Configure the thermostat to operate with the remote sensor (see Configuration Mode setting 9).

Note: Remote or outdoor sensor reading can be displayed by simultaneously pressing the DOWN and SYS buttons.

Terminal Designator Descriptions

• R: 24 VAC hot
• C: 24 VAC common
• W1: 1st stage heat
• Y1: 1st stage cool
• W2: 2nd stage heat
• Y2: 2nd stage cool
• G: Fan
• A: Alarm input
• L: Status input
• O: Override/reset
• S1, S2: Remote sensor connections

Testing the Thermostat

Once configured, the thermostat should be thoroughly tested.

CAUTION!: Do not energize the air conditioning system when the outdoor temperature is below 50 degrees. It can result in equipment damage or personal injury.

Heat Test

1. Press SYS [left] button until Heat mode is displayed.
2. Adjust set temperature 5 degrees above room temperature.
3. Heat should come on within seconds.
4. Adjust set temperature 2 degrees below room temperature; heat should turn off (may be a fan delay).

Cool Test

1. Press SYS [left] button until Cool mode is displayed.
2. Adjust set temperature 5 degrees below room temperature.
3. A/C should come on within seconds.
4. Adjust set temperature 2 degrees above room temperature; A/C should turn off (may be a fan delay).

Fan Test

1. Press FAN [right] button. "Fan" displays; indoor fan turns ON.
2. Press FAN [right] button. Indoor fan turns OFF.

Programming

The 910121748 programmable thermostat has four periods per day: MORN, DAY, EVE, NITE. Each period has a start time, heat temperature, cool temperature, and programmable fan option.

Setting the Time and Day of the Week:

1. Press SYS [left] button until OFF mode is displayed.
2. Press and hold PROG button (SYS [left] + FAN [right] buttons simultaneously) for 6 seconds.
3. Press FAN [right] button once to select hour (hour flashing). Adjust with UP/DOWN.
4. Press FAN [right] button once to select minutes (minutes flashing). Adjust with UP/DOWN.
5. Press FAN [right] button once to select day of the week (TODAY flashing). Adjust with UP/DOWN.
6. Press PROG button for 2 seconds to save and return to OFF mode, or press FAN [right] to enter programming.

Setting the Program Schedule:

From the OFF mode, press and hold PROG (SYS + FAN) for 6 seconds. Press FAN [right] 3 times. SUN thru SAT will blink.

You can program all 7 days at once, or select specific days.

Programming Steps:

1. Press FAN [right] to begin programming. The days shown will be programmed simultaneously.
2. MORN period blinks. Use UP/DOWN to select period (MORN, DAY, EVE, NITE).
3. Press FAN [right] to advance. Transition time hour blinks. Use UP/DOWN to select hour.
4. Press FAN [right] to advance. Transition time minutes blink. Use UP/DOWN to select minutes.
5. Press FAN [right] to advance. Heat set temperature displays. Use UP/DOWN to adjust.
6. Press FAN [right] to advance. Cool set temperature displays. Use UP/DOWN to adjust.
7. Press FAN [right] to advance. Programmable fan screen displays. Use UP/DOWN to select:
   • Off – Programmable fan disabled
   • On – Indoor fan on continuously

   Note: Programmable fan operates in Program mode only.

8. Repeat steps for all four periods per day.
9. When complete, press and hold PROG (SYS + FAN) for 2 seconds to return to OFF mode.

Factory Preprogramming:

The 910121748 comes preprogrammed with a schedule for Monday through Sunday:

Use the following personal program schedule to record your settings:

Troubleshooting

Company Information

Daikin Training and Development: For training information on all Daikin HVAC products, visit www.DaikinApplied.com and click on Training, or call 540-248-9646 and ask for the Training Department.

Warranty: All Daikin equipment is sold pursuant to its standard terms and conditions of sale, including Limited Product Warranty. Consult your local Daikin Representative for warranty details. Refer to Form 933-430285Y. To find your local Daikin Representative, go to www.DaikinApplied.com.

Aftermarket Services: To find your local parts office, visit www.DaikinApplied.com or call 800-37PARTS (800-377-2787). To find your local service office, visit www.DaikinApplied.com or call 800-432-1342.

This document contains the most current product information as of this printing. For the most up-to-date product information, please go to www.DaikinApplied.com.

Products manufactured in an ISO certified facility.