Lennox Equipment Interface Module (EIM)

Product Overview

The Equipment Interface Module (EIM) facilitates the use of a Lennox® Communicating Thermostat with most non-communicating HVAC systems. It allows conventional furnaces or air handlers (up to 3 stages heating and 2 stages cooling) to emulate a Lennox® Communicating indoor unit, with some communication features reduced. Most conventional outdoor/indoor units and Lennox® Communicating outdoor units can be used, but not Lennox® Communicating outdoor units with variable capacity.

Additional conventional indoor air quality products like PureAir™ Air Purification System, Healthy Climate® Humidifiers, Humiditrol® Enhanced Dehumidification Accessory, Healthy Climate® Energy/Heat Recovery Ventilators, and Healthy Climate® Germicidal Lights can be integrated for a comprehensive comfort system. A second EIM is required for "smart" ventilation with Healthy Climate® Energy/Heat Recovery Ventilators or Fresh Air Dampers.

EIM Module Features

• Contains necessary relays and controls to emulate a Lennox® Communicating indoor unit.
• Equipped with two green LEDs: one for status and troubleshooting, and another for active RSBus communication.
• Transmits system alerts and warnings to the Lennox® Communicating Thermostat.
• Utilizes a Serial Communications Bus (RSBus) for system communication, requiring less wiring than conventional systems.
• Connects to the Lennox® Communicating Thermostat using 4-wire, 18-gauge standard thermostat wiring.
• Connects to non-communicating indoor/outdoor unit equipment via conventional thermostat wiring.
• Jumpers are provided for the following settings: Unit Type (IFC, AHC, VENT - default furnace), Number of Heat Stages (0-3 - default 1 stage), and Heat Pump Capacity (1.5-5.0 - default 3.0).

Terminal Connections

• Communicating RSBus: R, I+, I-, C (To Lennox® Communicating thermostat)
• Non-Communicating: W1, W2, W3, G, Y2, Y1, C, DS, R, H, O, B (To conventional indoor/outdoor unit)
• Dual-Fuel: DFTS, w1-DEF, O, B (To non-communicating heat pump)
• Connections are also available for an Outdoor Air Temperature Sensor and Discharge Air Sensor (sensors must be ordered separately).
• The module is protected by a blade-type 3 amp fuse.

Case Specifications

• Constructed of high-impact ABS plastic.
• Features a hinged cover with latching tabs to prevent tampering.
• Can be mounted on the side of the indoor unit or a nearby stud or wall.
• Dimensions: 6-1/8 x 7-1/2 x 1-3/8 inches (156 x 191 x 35 mm).
• Weight: 1 lb.

Equipment Warranty

• Five years for residential installations.
• One year for non-residential installations.
• Refer to Lennox® Basic Limited Warranty at www.Lennox.com for additional details.

System Configuration Diagram

The system can be configured with a Lennox® S40 Smart Thermostat with Subbase or the Lennox® Smart Thermostat App. The system connects a Lennox® Communicating Outdoor Unit (Air Conditioner or Heat Pump) or a conventional Outdoor Unit (Air Conditioner or Heat Pump) to the Equipment Interface Module (EIM). The EIM then connects to a Conventional Furnace or Conventional Air Handler. An Outdoor Air Temperature Sensor and Discharge Air Sensor can be optionally connected. Healthy Climate® HRV (Heat Recovery Ventilator) or ERV (Energy Recovery Ventilator) or Fresh Air Damper can also be connected, potentially requiring a second EIM for "smart" ventilation.

LEGEND:

• RSBus: Red line
• Conventional Wiring: Blue line

EIM Connections Diagram

The EIM circuit board features labeled connection points for various components. These include:

• Outdoor Air Temperature Sensor connections
• Discharge Air Sensor connections
• Connections for "others" (labeled 1, 2, 3, 4)
• VENT connections (VENT1, VENT2, VENT C)
• Non-Communicating Connections (W1, W2, W3, G, Y2, Y1, C, DS, R, H, O, B)
• Dual Fuel Connections (DFTS, W1-DEF, O, B)
• A 3-Amp Fuse (F1)
• LED indicators
• Jumpers for Unit Type, Heat Stages, and Capacity
• RSBus connections (I+, I-, C)

Required Components

Lennox® S40 Smart Wi-Fi Thermostat

• Automatically configures and controls heating/cooling systems for optimal comfort, performance, and efficiency by recognizing Lennox® Communicating Products.
• Simplifies setup by recognizing model and serial number information of Lennox® Communicating products.
• Enables Wi-Fi remote temperature monitoring and adjustment via PCs, laptops, and the Lennox Smart Thermostat App.
• Compatible with smart home systems like Amazon Alexa®, Google Assistant, and CONTROL4®.
• Provides service alerts and reminders via text or email.
• Features a Service Dashboard for real-time online monitoring of installed thermostats.
• Offers a simple, user-friendly touchscreen interface for complete system configuration.
• Displays scheduled maintenance alerts, system warnings, and troubleshooting information.
• Boasts an easy-to-read 7-inch high-definition color display.
• Allows easy integration and control of conventional outdoor units.
• Installer setup screens facilitate quick system configuration and component testing.
• The Lennox Smart Technician App enables remote system management, testing, and refrigerant charge management without gauges.
• Uses RSBus for system communication with less wiring.
• Requires 4-wire, standard thermostat wiring.
• Includes High Definition Color Display with Subbase, Smart Hub Controller, and wallplate for easy installation.

Remote Outdoor Temperature Sensor

• Used with Lennox® Communicating thermostats to display outdoor temperature.
• Auto-detected when connected to the thermostat.
• Required for Humiditrol® applications.
• Furnished standard with Lennox® Communicating outdoor units; optional for conventional units.

Optional Accessories

Ventilation Damper

• Constructed of rolled galvanized steel with stiffening ribs.
• Features a single steel offset blade on a one-piece aluminum shaft with nylon bearings.
• Available in spring return, normally closed or normally open configurations.
• Requires a separate 24V transformer.

Transformer

• 120V primary, 24V secondary, 40VA transformer for powering the ventilation damper.

Ordering Information

¹ Remote Outdoor Temperature Sensor is used with conventional (non-Lennox® Communicating) outdoor units (sensor is furnished with Lennox® Communicating outdoor units). Allows the thermostat to display outdoor temperature. Required in dual-fuel and Humiditrol® applications.

² Optional for indoor air service diagnostics.

Revisions

• Document: Updated usage with S40 Smart Thermostat. Added Ventilation control.