Lennox International Inc 51M32 operation manual Cooling Control

Page 9

Heat Mode Disabled

ROOM 69

FAN

AUTO

SETPOINT 64 SYSTEM

OFF

Figure 6

Heating Demand

The thermostat must be in either normal or emergency heat mode in order to properly control the heating equip- ment. When in either heat mode, if the actual temperature is lower than the temperature setpoint, a heating demand is de- tected by the thermostat. The thermostat will then activate the heating equipment to satisfy the demand. Heating operation is indicated by a flame icon in the SYSTEM box as shown in figure 7.

Heating Demand

ROOM 72

FAN

AUTO

88 SYSTEM

HEAT

Figure 7

When the actual temperature rises above the temperature setpoint, the flame icon will disappear. This indicates that the heating demand has been satisfied and that the heating equipment has been turned off.

NOTE − The heat pump is activated for at least 4 minutes if no buttons are pressed during the demand interval. The backup heat source is activated for at least 3 minutes if no buttons are pressed during the demand interval.

Heat pump operation is locked out for 5 minutes after a de- mand has been satisfied. If another heat pump demand oc- curs during this 5−minute interval, the flame icon will flash; however, the heat pump will not run until the 5−minute delay has elapsed.

Cooling Control

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

Enabling and Disabling Cool Mode

Use the COOL button to enable or disable cool mode as necessary. If the thermostat is in off mode, cool mode is en- abled when the COOL button is pressed. This is indicated by COOL in the SYSTEM box.

If the thermostat is in cool mode, cool mode is disabled when the COOL button is pressed. This is indicated by OFF in the SYSTEM box.

Cooling Demand

The thermostat must be in cool mode in order to properly control the cooling equipment. When in cool mode, if the room temperature is higher than the temperature setpoint, a cooling demand is detected by the thermostat.

The thermostat will then activate the cooling equipment to satisfy the demand. Cooling operation is indicated by a snowflake icon in the SYSTEM box as shown in figure 8. When the actual temperature drops below the temperature setpoint, the snowflake icon will disappear. This indicates that the cooling demand has been satisfied and that the cooling equipment has been turned off.

Cooling Demand

ROOM 79

FAN

AUTO

SYSTEM

COOL

Figure 8

NOTE − The cooling equipment is activated for at least 4 minutes if no buttons are pressed during the demand inter- val. Cooling equipment operation is locked out for 5 min- utes after a demand has been satisfied. If another cooling demand occurs during this 5−minute interval, the snowflake icon will flash; however, the cooling equipment will not run until the 5−minute delay has elapsed.

Adjusting Temperature Setpoint

The temperature setpoint represents the desired tempera- ture of the space around the thermostat. The default tem- perature setpoint is 70°F. To adjust the setpoint, press the UP or DOWN arrow keys to the right of the display screen.

The existing setpoint will be displayed just below the actual room temperature as shown in figure 9. Use the UP or DOWN arrow keys to adjust the setpoint up or down. The setpoint will increase by 1°F each time the UP key is pressed. The setpoint will decrease by 1°F each time the DOWN key is pressed.

Page 3

Image 9
Contents Initial Thermostat Power-up Table of ContentsMeritR Series Thermostat GeneralHeat Mode Disabled Heat Mode EnabledHeating Control Display − Home ScreenEnabling and Disabling Cool Mode Adjusting Temperature SetpointSetpoint Display and Adjustment Cooling ControlFilter Reminder Fan ControlThermostat Reset Service IndicatorDefault Thermostat Settings Technical SpecificationsThermostat Output Table Controls 51M33 Emergency Heat Mode Additional Thermostat Buttons Normal Heat ModeNormal Heat Mode Enabled Emergency Heat Mode EnabledCooling Control Fan Control Balance Point Setting Service Indicator Flashing RoomBalance Point Backup Heat Source Selection 51M33 Terminal DesignationsBalance Point Thermostat Output Table Gas Heat Backup Dual Fuel − No Outdoor Sensor Electric Heat Backup − No Outdoor SensorElectric Heat Backup − Outdoor Sensor Attached Gas Heat Backup Dual Fuel − Outdoor Sensor Attached