NOTE:
For 81M26 single stage heat
pump applications, place a jumper
between the W1 and Y1 terminals.
7
Connect wiring between unit and
furnace. For Model 81M27
(2H/2C furnace applications):
8
Replace cover on thermostat.
Turn on power to unit and proceed
with programming per instructions on
the display or in the user’s manual.
11
Connect wiring between unit and
heat pump. For Model 81M28
(2H/2C heat pump applications):
9
To set your name and phone
number into the thermostat press
MENU, select INSTALLER
SETTINGS, and CONTACT
INFORMATION. The screen at the
bottom left should appear.
To enter your name press EDIT.
Use the UP or DOWN button to
scroll through the characters.
(DOWN gets you to the letters
faster.) After each letter press NEXT.
When you are done entering your
name, press ACCEPT.
Connect wiring between the
thermostat and the outdoor
sensor (46M98), if used. Use twisted
pair wiring (84X49) with a maximum
length of 300 feet (or 100m).
Seal the hole in the wall with a suit-
able material to prevent drafts from
entering the thermostat case.
10
NOTE: If the SignatureStat is being used
in conjunction with the G50UHI
furnace, you will need Lennox relay
#45H03.
If the SignatureStat is being used in
conjunction with any other furnace
that uses a single-speed, multi-tap
indoor blower, you will need Lennox
Indoor Blower Control Kit #40K58.
If the SignatureStat is being used in
a dual fuel application, you will need
dual fuel tempering kit #67M41.
Now enter your phone number.
Use the UP and DOWN arrow to
select the first number. Press NEXT.
When you have completed entering
your phone number, press ACCEPT.
The screen will return to the
INSTALLER SETTINGS. Finish
setting the thermostat for the
application.
Y1
R
C
E/W1
H O B G
Furnace
Thermostat
C - Common 24 VAC
R - System transformer
Y1 - 1st stage cooling
W1- 1st stage heating
W2- 2nd stage heating
Y2 - 2nd stage cooling
L
- System check
O - Cool active reversing valve
B - Heat active reversing valve
G - Fan relay
D - Dehumidification relay
H - Humidification relay
TERMINAL DESIGNATIONS
W2
D
Y2
C
C
H
R
Y1
W1
W2
Y2
L
G
L
B
O
* Please refer to furnace
installation manual for
proper terminations
Note: To avoid electrical problems, use the system transformer for both
the thermostat and humidifier.
81M27
Humidifier
Wiring Terminals*
DS
Y1
R
C
E/W1
H O B G
Heat Pump
Wiring
Terminals*
Thermostat
C - Common 24 VAC
R - System transformer
Y1 - Compressor output
W1- Emergency heat relay
W2- 2nd stage heating
Y2 - 2nd stage cooling
L
- System check
O - Cool active reversing valve
B - Heat active reversing valve
G - Fan relay
D - Dehumidification relay
(to DS terminal)
H - Humidification relay
(to Humidifier)
TERMINAL DESIGNATIONS
W2
D
Y2
C
C
H
R
Y1
E
W2
Y2
G
L
B
L
O
DS
* For most applications, E/W1 should
be jumpered to W2.
* Please refer to heat pump installation
manual for proper terminations.
Note: To avoid electrical problems, use the system transformer for both
the thermostat and humidifier.
81M28
Humidifier
Set Your Name
Set Your Phone Number
Y1
R
C
E/W1
H O B G
Heat
Pump
Terminals*
Wiring
Thermostat
C - Common 24 VAC
R - System transformer
Y1 - 1st stage cooling
W1- 1st stage heating
W2- not used
Y2 - not used
L
- System check
O - Cool active reversing valve
B - Heat active reversing valve
G - Fan relay
D - Dehumidification relay
H - Humidification relay
TERMINAL DESIGNATIONS
W2
D
Y2
C
C
H
R
Y1
W1
L
G
L
B
O
* Please refer to heat pump
installation manual for
proper terminations
Note: To avoid electrical problems, use the system transformer for both
the thermostat and humidifier.
81M26
Humidifier
DS
Jumper
CONTACT INFORMATION
BACK
EDIT
ACCEPT
NEXT
CONTACT INFORMATION
LENNOX
CONTACT INFORMATION
LENNOX
ACCEPT
NEXT
1
ACCEPT
NEXT
CONTACT INFORMATION
LENNOX
1-555-555-1212
12
13
111-318E
www.lennox.com
504,683M
