Lennox International Inc 51M32 Heating Control, Display − Home Screen, Heat Mode Enabled

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Display − Home Screen

ROOM 70

FAN

AUTO

SYSTEM

HEAT

Figure 2

Figure 2 illustrates the HOME screen. Note that an indoor room temperature of 70°F is initially displayed. After about 1 minute of warm−up time, the actual room temperature will be displayed. HEAT mode is the system default (as indi- cated in the SYSTEM box at lower right).

A pale blue display backlight will turn on each time a key is pressed. The backlight will turn off 8 seconds after the last key is pressed.

Heating Control

The HEAT button is located behind the small door on the right−hand side of the thermostat. See figure 3.

Additional Thermostat Buttons

Figure 3

Enabling and Disabling Heat Mode

Use the HEAT button to enable or disable heat mode as de- sired. If the thermostat is in off mode, heat mode is enabled when the HEAT button is pressed. This is indicated by HEAT in the SYSTEM box as shown in figure 4.

Heat Mode Enabled

ROOM 69

FAN

AUTO

SETPOINT 64 SYSTEM

HEAT

Figure 4

If the thermostat is in heat mode, heat mode is disabled when the HEAT button is pressed. This is indicated by OFF in the SYSTEM box as shown in figure 5.

Heat Mode Disabled

ROOM 69

FAN

AUTO

SETPOINT 64 SYSTEM

OFF

Figure 5

Heating Demand

The thermostat must be in heat mode in order to properly control the heating equipment. When in heat mode, if the actual temperature is lower than the temperature setpoint, a heating demand is detected by the thermostat. The thermo- stat will then activate the heating equipment to satisfy the de- mand. Heating operation is indicated by a flame icon in the SYSTEM box as shown in figure 6.

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Contents MeritR Series Thermostat Table of ContentsInitial Thermostat Power-up GeneralHeating Control Heat Mode EnabledHeat Mode Disabled Display − Home ScreenSetpoint Display and Adjustment Adjusting Temperature SetpointEnabling and Disabling Cool Mode Cooling ControlFan Control Filter ReminderDefault Thermostat Settings Service IndicatorThermostat Reset Technical SpecificationsThermostat Output Table Controls 51M33 Normal Heat Mode Enabled Additional Thermostat Buttons Normal Heat ModeEmergency Heat Mode Emergency Heat Mode EnabledCooling Control Fan Control Balance Point Balance Point SettingService Indicator Flashing Room Balance Point Backup Heat Source Selection51M33 Terminal Designations Thermostat Output Table Electric Heat Backup − Outdoor Sensor Attached Electric Heat Backup − No Outdoor SensorGas Heat Backup Dual Fuel − No Outdoor Sensor Gas Heat Backup Dual Fuel − Outdoor Sensor Attached