Configuration

Set Time and Date

Time

  1. Press MENU on the thermostat

  2. Press or to go to TIME and press SELECT

  3. Press or to choose 12 or 24 hour clock format and press NEXT

  4. Press or to adjust the hour and press NEXT.

  5. Press or to adjust the minute and press NEXT.

Date

  1. Press MENU on the thermostat.

  2. Press or to go to DATE and press SELECT.

  3. Press or to choose YEAR and press NEXT.

  4. Press or to choose MONTH and press NEXT.

  5. Press or to choose DATE and press SAVE and then EXIT.

System Setup

On initial setup the thermostat will enter the ISU menu. If entering the ISU menu after initial setup, follow the steps below:

  1. Press and hold the bottom left button and Up arrow button for 5 seconds to access the INSTALLER SETUP

  2. The display shows the ISU number on the left and the ISU setting on the right.

When an ISU number is displayed, press or to change the setting for that ISU.

  1. After choosing the correct setting for an ISU, press NEXT to advance to the next ISU setting.

  2. To finish setup, press the SAVE & EXIT button; this will save your settings and return to the Home screen.

Installer Setup Options (ISU)

Note: Depending on system settings, not all options may be available.

# ISU

ISU Name

ISU Options (factory defaults are bold)

1040

Scheduling Options (If you do not wish to set a schedule, use the default setting, then enter the Schedule Menu after completing setup and select Off)

1 = 1 week (all days the same)

2 = 5-2 Programmable (separate weekdays and weekend)

(The RTH20B only has the 5-2 day setting)

3 = 5-1-1 Programmable (separate Saturday and Sunday)

4 = 7-Day Programmable (each day separate)

1050

Temperature Indication Scale

F = Fahrenheit

C = Celsius

 (Default varies by model)

2000

Heating System Type

1 = Conventional Forced Air Heat

2 = Heat Pump

3 = Radiant Heat (Boiler)

5 = None (Cool Only)

If you are unsure what type of system you have, refer to your heating/cooling system equipment literature or call an HVAC professional. If you select the wrong system type, the thermostat will not operate the equipment as intended.

2010

Heating Equipment Type

Conventional Forced Air Heat:

1 = Standard Efficiency Gas Forced Air

2 = High Efficiency Gas Forced Air

3 = Oil Forced Air

4 = Electric Forced Air

5 = Hot Water Fan Coil (ISU 2010 not shown when 2000 = Heat Pump)

Radiant Heat:

9 = Hot Water Radiant Heat

12 = Steam

2060

Reversing Valve O/B

0 = O (O/B in Cool. O wire is connected to the O/B terminal and controls cooling.)

1 = B (O/B on Heat. B wire is connected to the O/B terminal and controls heat.)

The literature that came with your heat pump equipment should indicate whether the reversing valve is energized in Heat or Cool mode.

2070

Cool Stages/Compressor Stages

200 = Conv/200 = HP

0, 1, 2 (1 if 2000 = 2)

Only 1 compressor stage available on RTH20B/RTHC20B and RTH21B/RTHC21B. Select the number of Stages. For heat pumps, only 1 stage is supported.

2071

Heat Stages / Backup heat stages

Heat Stages: 1, 2

Backup Heat Stages: 0, 1 (RTH21B/RTHC21B and

RTH22B/RTHC22B)

2180

Aux Backup Heat Type (for Heat Pump Systems)

31=Electric Forced Air (This thermostat only supports electric backup heat. If your heat pump uses a gas or oil backup heat source, this thermostat should not be used.)

3000

System Changeover

0 = Hidden (Manual only)

1 = Enabled

(Automatic available. In Auto mode, the thermostat automatically

switches between heating and cooling to maintain the desired

indoor temperature. This option is not recommended if the outdoor

temperature often stays below 50°F [10°C] during winter months.)

4090

Smart Response

0=No

1=Yes (Smart Response is a comfort setting. Heating or cooling equipment will turn on earlier, ensuring the indoor temperature will match the setpoint at the scheduled time.)

4103

Minimum Heat Setpoint

32 °F to 50 °F (Default is 40 °F)

0 °C to 10.0 °C (Default is 4.5 °C)

Do not set this lower than 40°F/4.5°C unless installed in a location where pipes are not at risk of freezing.

7110

Air Filter Replacement Reminder

(Run Time only counts the time that Heat, Cool or Fan are running)

0 = Off

1 = 10 Run Time Days

2 = 20 Run Time Days

3 = 30 Run Time Days

4 = 45 Run Time Days

5 = 60 Run Time Days

6 = 90 Run Time Days

7 = 120 Run Time Days

8 = 150 Run Time Days

9 = 30 Calendar Days

10 = 45 Calendar Days

11 = 60 Calendar Days

12 = 75 Calendar Days

13 = 3 Calendar Months

14 = 4 Calendar Months

15 = 5 Calendar Months

16 = 6 Calendar Months

17 = 9 Calendar Months

18 = 12 Calendar Months

19 = 15 Calendar Months

14005

Idle screen selection

0 - Minimum Information shown

1 - Setpoint shown on Idle screen

2 - Maximum display information shown

14010

Clock format

12/24

14015

Daylight Saving Time

0 = Off

1 = On