Heat − Heat Mode - Lennox ComfortSense L3532H Operation Manual

HEAT − Using the Heat Mode
Normal Heat Mode
In normal heat mode, both the heat pump and the backup
heat source are used to provide heat. If the thermostat de-
tects that the heat pump is not able to provide enough heat
(as may be the case in very cold weather), then the backup
heat source is activated.
Emergency Heat Mode
In emergency heat mode, only the backup heat source
provides heat the heat pump is disabled. The backup
heat source is activated only when there is a heat demand.
Enabling Normal Heat Mode
Use the HEAT button to select normal heat mode, emer-
gency heat mode, or to disable heat modes as desired. If
the thermostat is in OFF or COOL mode, pressing the Heat
button enables Heat mode. This is indicated by HEAT in
the SYSTEM box as shown in figure 4.
MO
5:30
AM
FAN
PM
HOLD
AUTO
SYSTEM
66 ROOM
70 SETPOINT
°
°
HEAT
Figure 4. Turn Heat ON/OFF
Enabling Emergency Heat Mode
If the thermostat is in heat mode, pressing the Heat button
enables EMG. HEAT mode (see figure 5). If the thermostat
is in normal heat mode when the HEAT button is pressed,
then emergency heat mode is enabled.
ROOM
62
SETPOINT
°
Figure 5. Emergency Heat Mode Enabled
Disabling Heat Mode
If the thermostat is in emergency heat mode when the
HEAT button is pressed, then heat modes are disabled.
This is indicated by OFF in the SYSTEM box as shown in
figure 6.
Heat Cool
Prog Day/Time
Fan Hold
Settings Enter
SYSTEM
COOL
75
OFF
°
EMG.
HEAT
ROOM
75
°
Figure 6. Heat Mode Disabled
Heating Demand
The thermostat must be in either normal or emergency
heat mode in order to properly control the heating equip-
ment. In either heat mode, when the actual temperature is
lower than the temperature setpoint (as shown in figure 7),
the thermostat detects a heating demand and activates the
heating equipment to satisfy the demand. Heating opera-
tion is indicated by a flame icon in the SYSTEM box.
72
ROOM
°
Figure 7. Heating Demand
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 heat-
ing equipment has been turned off.
Heat pump operation is locked out for 5 minutes after a de-
mand has been satisfied. If another heat pump demand
occurs during this 5−minute interval, the flame icon will
flash; however, the heat pump will not run until the 5−min-
ute delay has elapsed.
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.
If your system supports 3−stage heating (as does the
L3532H thermostat), you may notice various heating lev-
els being delivered during a demand.
If a small heat pump heating demand is present, "Lo" is dis-
played in the SYSTEM box; if a large heat pump heating
demand is present, "Hi" is displayed (see figure 8).
ROOM
65
°
Figure 8. Large Heat Demand
Page 3
SYSTEM
SETPOINT
COOL
75
OFF
°
HEAT
SYSTEM
SETPOINT
COOL
75
° OFF
HEAT
SYSTEM
SETPOINT COOL
75
OFF
°
HEAT
L3532H 5/2 DAY PROGRAMMABLE THERMOSTAT
Hi