Lennox SignatureS
tat 81M26 Programming And Application Manual page 18

NOTE − In addition to non−heat pump single-stage applications, the
81M26 thermostat supports a single-stage heat pump with NO auxil-
iary heat source.
1ST STAGE HEATING Use the
81M27 thermostat's 1st stage
heating screen to choose gas/oil
or electric first−stage heating.
Use UP/DOWN buttons for desired selection; press SELECT.
AUXILIARY HEAT Use the
81M28 thermostat's auxiliary
heat screen. Use UP/DOWN but-
tons for desired selection; press
SELECT.
If using an electric furnace, select STANDARD − COMP = ON; if using
a gas furnace (dual fuel), use ADD ON − COMP = OFF).
4. BALANCE POINTS Balance point settings are only available on
the 81M28 thermostat. This screen appears only when optional out-
door sensor 46M98 is connected to the thermostat.
When sensor is used with the
81M28, you can set the lower and
upper temperatures to disable or
enable second stage heat.
Use the UP/DOWN buttons to select either LOW or HIGH BALANCE.
Press SELECT. Now use the UP/DOWN buttons to adjust the
balance point temperature. Setting range: −20F to +75F.
NOTE − High Balance cannot be set lower than the LOW setting; Low
Balance cannot be set higher than the HIGH setting.
5. RESIDUAL COOL To ensure greatest cooling efficiency, the indoor
blower can be programmed to run after a cooling demand has been
505232 06/07
HEATING/1ST STAGE HEATING
GAS / OIL
ELECTRIC
INSTALL MENU SELECT
AUXILIARY HEAT
STANDARD − COMP = ON
ADD ON − COMP. = OFF
BACK SELECT
BALANCE POINTS
LOW BALANCE 45 °F
HIGH BALANCE 75 °F
INSTALL MENU SELECT
Page 18
met by adjusting the residual cool setting. This is the amount of time
that the indoor blower will run after a call for cooling has been satis-
fied. This ensures that any residual cool air will be pushed out of the
ductwork and into the living area. Residual cool may interfere with
proper system operation, especially in humid climates.
Set residual cool to run for 30, 60,
90, or 120 seconds after the com-
pressor has shut off (default:
OFF).
6. AUTO CHANGEOVER / AUTOCHANGE DEADBAND When
AUTO CHANGEOVER (default − DISABLED) is turned ON, the ther-
mostat will switch automatically between heating and cooling to main-
tain the optimal temperature in the home.
From the INSTALLER SET-
TINGS menu, select AUTO
CHANGEOVER, then select EN-
ABLE.
The minimum allowable difference between the heating and cooling
setpoints is the auto changeover deadband (default − 4.0 degrees).
DEADBAND appears only when auto changeover is ENABLED as
described above. The deadband may be adjusted from 3.0 to 8.0 de-
grees in 0.5 degree increments.
From the INSTALLER SET-
TINGS menu select DEAD-
BAND. Use the UP and DOWN
arrows to adjust.
With default settings as described, the thermostat is essentially
shipped as a HEAT/COOL thermostat).
RESIDUAL COOL
SECONDS DELAY
OFF
INSTALL MENU SELECT
AUTO CHANGEOVER
DISABLE
ENABLE
INSTALL MENU SELECT
AUTOCHANGE DEADBAND
4ºF
INSTALL MENU SELECT