Lennox International Inc. 51M37 - Manual (Page 13)

Page 3
51M35 SERIES 5/2
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).
Heat
Prog
Fan
Settings
Cool
Day/Time
Hold
Enter
Turn Heat ON/OFF
Figure 4
5:30
66 70
HOLD
AM
PM
SETPOINT
ROOM
FAN
AUTO
SYSTEM
HEAT
MO
°
°
If the thermostat is in heat mode, pressing the Heat button
disables HEAT mode (indicated by OFF in the SYSTEM
box − see figure 5).
SYSTEM
COOL
OFF
HEAT
75
Heat/Cool Mode Disabled
Figure 5
ROOM
° 75
SETPOINT
°
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.
SYSTEM
COOL
OFF
HEAT
72
Figure 6
ROOM
° 75
SETPOINT
Heating Demand
°
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.
If your system supports 2−stage heating (as does the
51M35 thermostat), you may notice various heating levels
being delivered during a demand.
NOTE − Heating equipment is activated for at least 3 min-
utes if no buttons are pressed during the demand interval.
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 8).
Turn Cool ON/OFF
Figure 7
I0:30
75 70
HOLD
AM
PM
SETPOINT
ROOM
MO
° °
Heat
Prog
Fan
Settings
Cool
Day/Time
Hold
Enter
FAN
AUTO
SYSTEM
COOL
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.
75
Cooling Demand
Figure 8
ROOM
° 70
SETPOINT
SYSTEM
COOL
OFF
HEAT
°
Hi
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.
If your system supports 2−stage cooling (as does the
51M35 thermostat), you may notice various cooling levels
being delivered during a demand. Also, if a small cooling
demand is present, "Lo" will be displayed in the SYSTEM
box. However, if a large cooling demand is present, "Hi" will
be displayed in the SYSTEM box (shown in figure 8).
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.