Lennox Merit 51M37 Operation Manual page 21

HEAT − Using the Heat Mode
Enabling and Disabling Heat Mode
The thermostat must be in the HEAT mode to control the
heating equipment. Press the Heat button to enable or dis-
able HEAT mode. If the thermostat is in COOL or OFF
mode, pressing the Heat button enables the HEAT mode
(indicated by HEAT in the SYSTEM box − see figure 4).
Turn Heat ON/OFF
MO
5:30
AM
FAN
PM
HOLD
AUTO
SYSTEM
66 ROOM
70 SETPOINT
°
°
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/Cool Mode Disabled
ROOM
75
SETPOINT
°
Figure 5
Heating Demand
Set the thermostat to heat mode to control the heating
equipment. Then, if the room temperature is lower than the
temperature setpoint, as shown in figure 6, the thermostat
detects a heating demand and will activate the heating
equipment to satisfy the demand.
Heating Demand
72
ROOM
SETPOINT
°
Figure 6
Heating operation is indicated by a flame icon in the SYS-
TEM box. 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 − Heating equipment is activated for at least 3 min-
utes if no buttons are pressed during the demand interval.
Heat Cool
Prog Day/Time
Fan Hold
Settings Enter
SYSTEM
COOL
75
OFF
°
HEAT
SYSTEM
COOL
75
OFF
°
HEAT
COOL − Using the Cool Mode
Enabling and Disabling Cool Mode
Use the COOL button to enable or disable cool mode as
desired. If the thermostat is in HEAT or OFF mode, cool
mode is enabled when the COOL button is pressed. This is
indicated by COOL in the SYSTEM box (see figure 7).
MO
I0:30
AM
PM
HOLD
SYSTEM
75 ROOM
70 COOL
SETPOINT
°
°
If the thermostat is in cool mode, pressing the Cool button
disables COOL mode (indicated by OFF in the SYSTEM
box − see figure 5).
Cooling Demand
Set the thermostat to cool mode to control the cooling
equipment. Then, if the room temperature is higher than
the temperature setpoint, as shown in figure 8, the thermo-
stat detects a cooling demand and will activate the cooling
equipment to satisfy the demand.
Cooling Demand
ROOM
75
°
Cooling operation is indicated by flashing snowflake"
icons in the SYSTEM box. When the actual temperature
drops below the temperature setpoint, the snowflake icons
will disappear. This indicates that the cooling demand has
been satisfied and that the cooling equipment has been
turned off.
NOTE − If no buttons are pressed during a demand for
cooling, the equipment must operate for at least 4 minutes.
After a demand has been satisfied, cooling equipment op-
eration is locked out for 5 minutes. If another cooling de-
mand occurs during this 5−minute interval, COOL" and the
snowflakes will flash; however, the cooling equipment will
not operate until the 5−minute delay has elapsed.
Page 3
Turn Cool ON/OFF
Heat Cool
FAN
Prog Day/Time
AUTO
Fan Hold
Settings Enter
Figure 7
SYSTEM
SETPOINT
COOL
70
OFF
°
HEAT
Figure 8
51M34 SERIES 5/2