Lennox S40 Installation And Setup Guide

6
Lennox
Communicating
Outdoor Unit
Lennox
Communicating
Thermostat
Indoor Unit Communicating Control
(Using 2-conductor Unshielded Cable for Communication Lines and
Separate 2-conductor Unshielded Cable for R and C)
OPTION 3
18/2 Brown Solid CU CL2 Thermostat Wire
Figure 4. Lennox Communicating System Wiring Connections using
Separate Unshielded Cable (Option 3)
Minimizing Electrical Noise
When using multi-conductor unshielded thermostat cable, to minimize electrical
noise, cap unused wires as illustrated below and run to indoor unit C terminal.
Single wire
to indoor unit
terminal “C”.
Unused
wires
Single wire directly to
C terminal or
to second bundle.
.
Indoor Unit Controller
Outdoor Unit
Thermostat
R i+ I- C
Unused
wires
Figure 5. Minimizing Electrical Noise

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