Lennox S40 Installation And Setup Guide

7
Application Specic Wiring Diagrams
24VAC 1- or 2-Stage
Heat Pump or
Air Conditioner
SETUP NOTES:
DATS (Optional)
OATS (Optional)
Thermostat
Lennox Communicating
Air Handler Unit
Heat Pump Only
Cut Y1-Y2 on-board link for 2-stage outdoor units
(Non-communicating)
Cut R-O on-board link for outdoor heat pump units
(Non-communicating)
(See Lennox
Communication
Wiring Diagram)
Figure 6. Lennox S40, Lennox Communicating Air Handler with 24VAC
(1- or 2-Stage) Heat Pump or Air Conditioner
+- AB ODT
FLOAT
Switch
DH DH
Gh Rf Cf Gs YW
HVAC EQUIP
.
DH
C
G
R
NC NO
NC
NO
SPDT RELAY
཰
ི
ཱ
ཱི
Thermostat
Lennox
Communicating
Indoor Unit
(See Lennox
Communication
Wiring Diagram)
Figure 7. Lennox S40, Communicating Indoor Control (Conventional
Connections), Relay and HCWHD4 Series Dehumidiers

Lennox S40 Specifications

General

Display	Color touchscreen
Voice Control	Amazon Alexa, Google Assistant
Energy Reports	Yes
Programming	7-day programmable
Warranty	5-year limited warranty
Connectivity	Wi-Fi
Compatibility	Lennox HVAC systems
Smart Features	Geofencing
Sensors	Temperature, Humidity