Lennox International Inc 51M37 operation manual I026

		Reminders
PROG	MO	I0:26
	AM
A B C D
HOLD PM

To adjust the balance point up or down, press the Up/Down arrow buttons to the right of the display screen. The bal- ance point setting increases by 1°F each time the Up but- ton is pressed and decreases by 1°F each time the Down button is pressed. After the desired balance point setting is

FAN ON

AUTO

FILTER SERVICE

MAINTENANCE

ROOM

76°

COOL

OFF

AUTO

EMG.

HEAT

Filter &

Maintenance

Indicators

reached, the HOME screen will reappear after about 15 seconds.

NOTE − The balance point feature allows the outdoor tem- perature to rise or fall 3°F above or below the balance point. This prevents excessive cycling of the equipment when the outdoor temperature is near the balance point. For example, if the balance point is 40°F and the actual

FAN ON

AUTO

FILTER SERVICE

MAINTENANCE

ROOM

76°

COOL

OFF

AUTO

EMG.

HEAT

Service

Indicator

Flashing

outdoor temperature is 35°F, the outdoor temperature must rise to 43°F before equipment adjustment occurs. Conversely, if the balance point is 40°F and the actual out- door temperature is 45°F, the outdoor temperature must drop to 37°F before equipment adjustment occurs.

Service Indicator

When abnormal equipment operation is detected, the

Figure 19

After the filter has been changed or maintenance per- formed, reset the reminder by pressing the SETTINGS button for 4 seconds at the corresponding reminder set- tings screen. The screen will blink for a few moments to in- dicate that the timer has been reset.

SETTINGS − Balance Point

NOTE − The balance point is only available with the out- door sensor.

When the outdoor sensor (X2658) is connected to the 51M42 thermostat, balance point adjustment is available. The balance point feature allows the measured outdoor temperature to govern operation of the heat pump and backup heat source.

Press the SETTINGS button three times to access the Bal- ance Point Settings screen (see figure 20).

Balance Point Setting

SETPOINT

6p 55°

Figure 20

The balance point can be set at any temperature between 1°F and 55°F (−17°C to 13°C). A balance point setting of zero disables the balance point function (in this case, the thermostat behaves as if no outdoor sensor is attached). The default balance point setting is 55°F.

SERVICE indicator will flash on the screen (see figure 19 on page 7). This indicates that the equipment requires service from a qualified service technician.

Thermostat RESET

Under some abnormal conditions, it may be necessary to the thermostat to its default condition. Such a RE-

SET would delete all programming and settings and there- fore should only be used on rare occasions when the the thermostat fails to function as designed and/or as pro- grammed. Such an instance can occur as a result of a pow- er surge or similar electrical disturbance (e.g. after an elec- trical storm or power outage). The RESET button can be used to recover from this situation.

CAUTION

When the RESET button is pressed, ALL settings re- vert back to the defaults, including the default pro- gram (see tables 2 and 3).

The RESET button is an unlabeled, recessed button lo- cated behind the door, on the right−hand side of the ther- mostat, below the SETTINGS button (see figure 3). Use a paper clip or small pencil to press the RESET button; ALL thermostat settings will be reset to the defaults listed in the Default Thermostat Settings section.

Removing/Installing Thermostat

The thermostat hinges on tabs on the top of the subbase; no tool is needed to remove the thermostat from the sub- base. Pivot the bottom of the thermostat outward (releas- ing the snaps), then lift up to remove.

To replace it, first position the top tilted toward the wall bracket and align it until you feel the tabs and slots engage; then, while the top is in place, pivot the bottom toward the wall until the thermostat snaps into place.

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51M42 SERIES 5/2