LENNOX 508466-01 Low Global Warming Potential Refrigerant Detection System Installation Guide

Installation Guide for LENNOX models including: 508466-01, 508466-02, 508466-01 Low Global Warming Potential Refrigerant Detection System, Low Global Warming Potential Refrigerant Detection System, Potential Refrigerant Detection System, Refrigerant Detection System, Detection System

INSTALLATION AND SETUP GUIDE

18 янв. 2025 г. — WARNING. All systems charged with at least 4 lbs of R-454B refrigerant are required to have a refrigerant leak detection system.

28 gen 2025 — WARNING. All systems charged with at least 4 lbs of R-454B refrigerant are required to have a refrigerant leak detection system.

[PDF] INSTALLATION AND SETUP GUIDE - Lennox

When the RDS Blower Control Board detects refrigerant: ... Fault. Reset the RDS Blower Control. Board after troubleshooting and resolving a fault condition.

File Info : application/pdf, 28 Pages, 1.92MB

508466-01c

©2025 Lennox Industries Inc. Dallas, Texas, USA
This manual must be left with the owner for future reference.
NOTE: Twinning of furnaces is not permitted with the Refrigerant Detection System Kit!

INSTALLATION AND SETUP GUIDE
Low Global Warming Potential (GWP) Refrigerant
Detection System (RDS) Communicating Control Board
(RDS Field Kit - Communicating)
CONTROLS 508466-01 02/2025
Supersedes 10/2024

Contents

Certifications ..............................................................3 Shipping and Packing List .........................................3 Overview....................................................................3 Operating Environment Specifications ......................3 Product Features .......................................................4 Introduction ................................................................5 Dimensions ................................................................6 Installation .................................................................7
Sensor Part Number Verification........................................ 7
Mounting Methods.............................................................. 7
Mounting Location.............................................................. 7
Routing the Sensor Cable .................................................. 9
Connecting the RDS Sensor ............................................ 10 Secondary Sensor ................................................... 11
Additional Line Set Joints ................................................ 11
Multiple Systems Installed in Same Space .................... 11 DIP Switch Settings .................................................12 Modes of Operation .................................................12
Initializing ........................................................................12
Normal.............................................................................. 12
Refrigerant Detected ........................................................ 13

Sensor Not Connected..................................................... 13
Fault ................................................................................. 13 Diagnostic Codes ....................................................13
Red LED Diagnostic Codes ............................................. 14 Test Button Functionality .........................................15
Test Button - Additional Functions.................................... 15 Thermostat Compatibility.........................................16
Compatibility Verification.................................................. 16 Additional Applications.............................................16
Zone HVAC System ......................................................... 16
External Alarm..................................................................17 Start Up Test Procedure ..........................................17
Cooling Demand ..............................................................17
Heating Demand ............................................................. 17 Wiring Diagrams ......................................................19 Diagnostic Codes and Troubleshooting...................26

WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life.
Installation and service must be performed by a licensed professional HVAC installer (or equivalent) or a service agency.
WARNING
All systems charged with at least 4 lbs of R-454B refrigerant are required to have a refrigerant leak detection system installed to prevent the build up of R-454B refrigerant in enclosed spaces of the HVAC equipment. A refrigerant detection system may be required for systems that have less than 4 lbs of R-454B refrigerant. For more information on this, contact Lennox Technical Support.
Installing a residential HVAC system that uses R-454B refrigerant without a refrigerant detection system may lead to a fire hazard within the home in the event of a refrigerant leak.
WARNING
The Lennox® RDS Blower Control Board has been tested with Lennox® coils only. Do not use a non-Lennox refrigerant detection system controller or non-Lennox leak sensor with Lennox® coils. Do not use the Lennox® RDS Blower Control Board with non-OEM coils or air handlers.

WARNING
Improper installation of the RDS Blower Control Board may lead to unreliable equipment operation and unreliable refrigerant detection.
In addition to installing the RDS Blower Control Board, considerations must be made regarding sensor mounting location. Please refer to respective Lennox air handler, coil, and/or sensor kit installation guides for further details.
CAUTION
It is the responsibility of the licensed installer or service agency to obtain the appropriate training and/or certifications to service A2L-classified HVAC systems with R-454B refrigerants.
CAUTION
Unit must remain powered except during service.

Certifications

Operating Environment Specifications

· CSA C22.2 No. 60335-2-40:22; Fourth ed. · UL 60335-2-40; Fourth ed.

Shipping and Packing List

Qty

Description

1 Lennox® Communicating Low GWP Refrigerant Detection System Kit
2 Mounting Hardware #6-18 1" Phillips Drive pan head with dry wall anchor

Cat. No. 27A03
N/A

The Low GWP Refrigerant Detection Kit is designed to withstand the following conditions:

Condition

Temperature Range

Normal Operation Shipping/Storage

-40°F - 185°F (40°C - 85°C)

Functional Range

Humidity

10% to 90% noncondensing at 104°F (40°C)

NOTE:

This kit is sold separately from the refrigerant detection sensor. The refrigerant sensor is included as part of a Lennox sensor kit, R-454B only coil, or R-454B only air handler.

Overview
Lennox® Low GWP Refrigerant Detection System, also referred to as RDS Blower Control Board, ensures safe operation of Lennox residential HVAC systems equipped with R-454B refrigerant. The RDS Blower Control Board connects to the refrigerant detection sensor, the indoor unit, the outdoor unit, and the thermostat to control the HVAC system in the event refrigerant is detected by the sensor. The RDS Blower Control Board functions with standard 24VAC or Lennox-communicating control interfaces.

Product Features
· Communicating Control Board and Sensor can be used universally with any Lennox® communicating furnace or any non-communicating 24-volt furnace
· Complies with UL 60335-2-40 approved standard · Required for all systems using R-454B refrigerant · Connects to the RDS sensor furnished with the RDS Coil Sensor Kit · Used as interface between indoor unit and thermostat to control system in case of refrigerant
detection · Ensures safe operation for systems equipped with R-454B refrigerant · Prevents compressor and heating operation (if refrigerant is detected) until safe refrigeration
levels are met · Engages the blower if refrigeration is detected to mitigate any concentrations of refrigerant from
the conditioned space · Multi-color LED (light-emitting diode) for system status and as an aid in troubleshooting · Alarm relay can trigger an external alarm if refrigerant is detected · Zone relay opens all zone dampers (if part of a zoning system) if refrigerant is detected · Disables power to non-communicating thermostats to prevent demand if refrigerant is detected · Composite case with mounting hardware for drywall installation
4

Introduction
The Lennox® Low GWP Refrigerant Detection System ensures safe operation of Lennox residential HVAC systems equipped with R-454B refrigerant.
The RDS activates the blower if refrigerant levels within the cabinet reach 12% of the lower flammability limit (LFL).
Power to all ignition sources within the HVAC system is automatically shut down until the RDS detects safe refrigerant levels. The RDS restores power to ignition sources after it detects refrigeration concentrations are safe. The HVAC system will then resume normal operation.

Cover

Sensor Selection DIP Switch Leak Event Test Button RDS Sensor Connection

RDS Blower Control Board

Thermostat & Condenser
Unit Terminals

Indoor Unit
Terminals

Back Plate

Communicating Zoning Alarm Dry Communicating Thermostat TB Terminal Terminal Indoor Unit /
Equipment TB
Figure 1. RDS Communicating Control Board

Dimensions

Top View
(7-7/16 in.)

Side View

Front View
(6-3/4 in.)

Rear View

(7-7/16 in.)

(6-3/4 in.)

(3-5/8 in.)

(2-1/2 in.)

(3-5/8 in.)

Boom View

(1-1/8 in.) (1-3/8 in.)

Figure 2. RDS Communicating Control Board - Dimensions 6

Installation

vironment that is away from dust, water, and other contaminant accumulation.

Sensor Part Number Verification

NOTE:

Verify the refrigerant detection system sensor's part number, which is found on the sensor/ cable, prior to installation. The part number is 107648-01.

Mounting the RDS Blower Control Board farther than 48 inches away from the refrigerant sensor may prevent reliable operation due to cable strain and water seepage on cable connections.

NOTE:

All sensors paired to a single RDS Blower Control Board must share the same part number (107648-01) to ensure the RDS Blower Control Board will function properly.

· Do not place the RDS Blower Control Board in secondary drain pan
· Use the screws provided to mount the RDS Blower Control Board

Mounting Methods

· Tighten the screws to a snug fit

Some mounting surfaces may be difficult to access after the RDS Blower Control Board is installed. Lennox suggests wiring the RDS Blower Control Board unit prior to mounting in a confined space.
For drywall/closet installations, use the included drywall hardware. For attic/crawlspace/basement installations, use the included and field-provided hardware.
Mounting Location

NOTE:

Do not over-tighten the screws. Over-tightening the screws may strip the hardware and apply excessive stress on the enclosure.

Refrigerant Detection System Sensor
The refrigerant detection system sensor must be mounted as specified in its accompanying manual. Mounting the sensor incorrectly or in an improper location may result in refrigerant detection failure.

The RDS Blower Control Board can be mount-
ed to the indoor unit, plenum, a stud, or joist in an attic, crawlspace, or other unfinished area within 48 inches of the refrigerant sensor cable
grommet on the coil or air handler. Drywall an-
chors and screws are provided for installation in finished areas, such as closets. Mount the RDS Blower Control Board in a clean, dry en-

Condensate Safety Switch (Float Switch)
In applications that require a condensate safety switch, a (field-provided) isolation relay must be installed with the float switch. The relay NO (normally open) contacts must be wired between "Y" and "DS" at the indoor unit control board and the (W914) jumper must be cut. See "Communicating Indoor Controls and Float Switch" on page 19.
Refrigerant Detection System Sensors
The Lennox Refrigerant Detection System requires a Lennox RDS sensor located in the indoor coil. See table below.

Indoor Unit Model
· CK40CT Upflow · CK40HT Horizontal · CK40DT Downflow
"Revision 01" Coils
All Lennox R-454B Coils & Air Handlers

RDS Blower Control Board Sensor Catalog Number

Description

26Z69

Refrigerant Detection System Coil Sensor Kit

27V53

Coil Sensor Repair Kit
(Replacement Sensor only, without mounting bracket & components provided in the Sensor Kit)

Routing the Sensor Cable
Figure 3 illustrates how to best route the sensor cable from the RDS Blower Control Board to the sensor within the indoor unit for the Upflow, Downflow, and Horizontal orientations. For details on mounting the sensor itself, refer to the respective sensor kit, air handler, or coil installation guide.

UPFLOW INDOOR UNIT SENSOR CABLE DRILL OUT
RDS COIL

DOWNFLOW INDOOR UNIT RDS

DRIP LOOP

COIL

HORIZONTAL INDOOR UNIT

COIL

RDS

DRIP LOOP

SENSOR CABLE DRILL OUT

DRIP LOOP

Figure 3. Routing the Sensor Cable

WARNING
Do not strap the RDS Blower Control Board to existing tubing or other electrical cables.

Connecting the RDS Sensor Ensure the cable is properly seated into the SENSOR 1 plug. The Molex plug clip should lock into the Molex connection point for a secured connection, as shown below in Figure 4. Verify the connection is free of dust, debris, and moisture. NOTE: In confined space applications, connect the second sensor to the SENSOR 2 plug.
Molex Plug Clip
Figure 4. Connecting the RDS Sensor to RDS Blower Control Board
10

Secondary Sensor Additional Line Set Joints
If additional joints are present outside of the line set sleeve, the system installation must comply with one of the options listed. Refer to Refrigerant Detection Sensor Kit Installation Instructions Form# (508467-01); see Line Set Joints. Multiple Systems Installed in Same Space For any Low GWP refrigerant system with additional joints not covered by line set joint sleeves, each system in the same space must have refrigerant detection sensor installed below the level of the burners. If a secondary refrigerant sensor is required, it must be mounted as follows: · Upflow Applications: Mounted on an unused side furnace return air connection at least nine
(9) inches above the floor and within nine(9) inches from front of furnace. · Horizontal Applications: Mounted on the lower section of the side return furnace air
connection, within nine(9) inches of both the blower deck and front of furnace. · Downflow Applications: Mounted on one side of the evaporator coil nine(9) inches above
the floor and within nine(9) inches from front of coil. Connect the refrigerant sensor to the second sensor input on the RDS Control. Refer to the instructions provided with the sensor or the RDS controller to enable the second sensor (see "DIP Switch Settings" on page 12).
11

DIP Switch Settings
Default Switch DIP Settings
The following are the default DIP switch settings: · DIP Switch 1 OFF · DIP Switch 2 OFF
The default setting requires the RDS Control Board to have two (2) sensors installed.
The sensor settings must be adjusted according to the number of sensors installed. If a second sensor is not installed (in Sensor 2 plug), DIP Switch 2 must be turned to the ON position.
Non-Default Configurations

Each DIP switch corresponds to a sensor position (i.e., DIP switch 1 to sensor 1; DIP switch 2 to sensor 2). The default factory switch positions are set to OFF. The RDS Blower Control Board software reads the OFF position as an active sensor. A sensor should be present for the corresponding sensor connector. Setting the DIP switch to ON disables the sensor position.

NOTE:

Refer to 508467-01 (Installation Instructions for Refrigerant Leak Detection Sensor Kit - Indoor Coils) to determine whether more than one (1) Refrigerant Detector Sensor is required.

Modes of Operation

Adjust the DIP switch settings to the sensor
configuration. Failure to do so will cause faults on power-up.

The modes of operation for the RDS Blower Control Board are Initializing, Normal, Refrigerant Detected, and Fault.

Table 1. DIP Switch Settings

Configuration Switch Switch Switch Switch

One (1) sensor,

connected to

OFF

N/A

SENSOR 1 plug

Two (2) sensors,

connected to SENSOR 1 plug and

OFF

N/A

SENSOR 2 plug

In single sensor configurations, the sensor must be connected to the SENSOR 1 plug.
Configurations other than the ones shown in Table 1 will cause a service fault.

Initializing
The RDS Blower Control Board is establishing connection with the refrigerant detection sensor and is completing an initial five-minute purge sequence.
Normal
The HVAC system is functioning normally. The RDS Blower Control Board has not detected refrigerant.

Refrigerant Detected

Sensor Not Connected

When the RDS Blower Control Board detects refrigerant:
1. The RDS Blower Control Board shuts off the (R) input (24VAC power) to the thermostat, which de-energizes the outdoor unit compressor and heat sources, such as gas and/or electric strip heat. No heating or cooling demands will be met.
2. The RDS Blower Control Board activates the blower (high speed). The blower purges refrigerant from the cabinet, plenum, and ductwork.
3. After the RDS Blower Control Board determines the refrigerant levels are below the UL standard threshold, the blower will continue to operate for the remainder of the seven (7) -minute cycle.

If no sensors are connected to the RDS Control Board, the LED will flash red four (4) times, indicating a service fault (sensor communication issue). Heat/Cool operation is still permissible and the blower motor will run continuoulsly at a high speed.
Fault
When a fault is detected within the RDS Blower Control Board, the indoor unit blower engages and remains engaged at a constant output until the fault is cleared.
Diagnostic Codes
The RDS Blower Control Board is equipped with a multicolor LED within its enclosure. The LED signals the state of the RDS Blower Control Board.

4. After the blower sequence is complete, the See Table 2 to review the diagnostic codes. HVAC system resumes normal operation.

NOTE:

The HVAC system may not maintain a cooling or heating setpoint if a significant leak exists. Any refrigerant leaks that remain unaddressed for an extended time may cause the HVAC system to shut down on a low refrigerant pressure limit condition.

Table 2. LED Diagnostic Codes

State
Initializing Monitoring
Mitigating (Refrigerant Detected)

LED Diagnostic
Code

Action

Flashing green¹

Not Applicable

Solid green with blue flash²

Not Applicable

Flashing blue

Check coil tubes for leak. Repair the issue and restart the equipment.

Table 2. LED Diagnostic Codes

State

LED Diagnostic
Code

Action

Fault/Service

Solid blue, interrupted by issue flash code

Refer to Table 7 for troubleshooting steps.

1. A rapid flash indicates the RDS Blower Control Board is in the process of sensor enumeration

2. A blue flash indicates a purge has previously occurred.

Red LED Diagnostic Codes
Red diagnostic codes indicate a specific RDS Blower Control Board issue. Yellow diagnostic codes indicate the sensor's position (if applicable).

Table 3. Red LED Diagnostic Codes

Red Applies to Flash Individual
Sensor(s)

Issue

Action

Yes

Sensor indicates fault

Replace the sensor
(Cat. # 27V53)

Spare Code Unused

Not Applicable

Replace with

Yes

Incompatible a compatible

sensor type

sensor

(Cat. # 26Z69)

Table 3. Red LED Diagnostic Codes

Red Applies to Flash Individual
Sensor(s)

Issue

Action

· Verify sensor DIP switch settings are correct.

Sensor

· Verify sensor

Yes communications connection is

issue

secure.

· Ensure connection is clean and free of debris.
· Check wiring connections.

· Ensure the

Indoor unit wiring connected incorrectly to the
"Black TSTAT" terminal strip on

indoor unit is wired to the "Blue INDOOR" terminal strip.

the RDS Non- · Verify the Communicating Room Control Board Thermostat
is wired to

the "Black

TSTAT"

terminal strip.

Verify the DIP

switch setting

Invalid

is correct and

No configuration of matches the

sensor count number of

sensors being

used.

Test Button Functionality
The RDS Blower Control Board is equipped with a Test/Reset button. The Test button can be used to complete several functions, depending on the mode of operation of the RDS Blower Control Board.

Test Button - Additional Functions
Table 5 lists the additional functions of the Test Button while the RDS Blower Control Board is functioning within the states of Initializing, Monitoring, Refrigerant Detection, Servicing and Fault. Refer to "Table 2. LED Diagnostic Codes" on page 13.

Table 4 lists the functions of the Test button during each mode of operation.

Table 4. Test Button Function

Mode of Operation
Normal
Refrigerant Detected
Fault

Press the Test Button to...
Trigger a refrigerant detection response. Verify all equipment is wired correctly into the RDS Blower Control Board (after installation). Reset the RDS Blower Control Board to a normal mode of operation after refrigerant has been detected and purged from the HVAC system. Reset the RDS Blower Control Board after troubleshooting and resolving a fault condition. If the fault is not resolved, the RDS Blower Control Board will enter the Fault mode again.

Table 5. Additional Button Functions

State
Initializing Initializing Monitoring Monitoring Mitigating Servicing Servicing
Fault Fault

Press
Short Long Short Long Short Short Long Short Long

Action
Skips remaining prepurge after sensors are recognized by the RDS Blower Control Board Reset control Clear purge-counter if prior mitigation has occurred; Test mitigation Reset control
If testing mitigation, end test
Reevaluate fault condition - if cleared return to monitoring, otherwise update indicator
Reset control
Reevaluate fault condition - if cleared return to monitoring, otherwise update indicator Reset control

Thermostat Compatibility

Compatibility Verification

Complete the following process to determine

Thermostats that preserve memory settings whether the thermostat is compatible with the are compatible with the RDS Blower Control RDS Blower Control Board.

Board. Examples include:

1. Change the thermostat's current setpoint

· Battery-powered thermostats

and operating mode.

· Analog thermostats

2. Power cycle the breaker to the furnace.

· Smart thermostats

NOTE: Wait five (5) minutes before

· Lennox communicating thermostats (S30 or S40)

supplying power to the furnace breaker.

· Late-model programmable thermostats

NOTE:

Early-generation digital and programmable thermostats may not retain the operation mode and temperature setpoints after a power outage.

3. Note whether the thermostat maintained its setpoints and operating mode.
a. If the thermostat maintained the settings, the thermostat is compatible with the RDS Blower Control Board.
b. If the thermostat did not maintain its setpoint and/or operating mode,

The following scenarios are likely to occur when home occupants are not available to ad-

the thermostat is not compatible with the RDS Blower Control Board.

just the thermostat setpoints as the system is

Recommend a compatible thermostat.

recovering from refrigerant detection and re-

suming normal operation:

Additional Applications

· Heating could be lost during a cold night
· Cooling could be lost during a hot day
· The thermostat could reset to an incorrect temperature setpoint

In zoned applications, all dampers will remain open when the RDS Blower Control Board is in Fault or Refrigerant Detected mode. Normal heating and cooling demands are permissible, but the blower will remain engaged until the fault condition is addressed.

Zone HVAC System
If the RDS Blower Control Board is installed in a zone HVAC system, the RDS Blower Control

Board will open all zone dampers if refrigerant is detected.

NOTE:

Proper wiring of the zone panel to the RDS Blower Control Board is required for all zone dampers to open.

After the purge sequence is complete, the zone system will resume normal operation.
External Alarm
(For applications with external alarms wired directly to the RDS Blower Control Board.)
The RDS Blower Control Board triggers the external alarm system when it enters Refrigerant Detected mode. For alarm notifications, the RDS Blower Control Board provides a dry relay contact that is rated 3A at 30 VAC/DC.

Start Up Test Procedure

The RDS Blower Control Board is equipped with a Test/Reset button, see "Test Button Functionality" on page 15. "After the RDS Blower Control Board has been mounted and wired, restore power to the HVAC system. The system will then run through a purge sequence for five minutes. After the purge sequence is complete, proceed to testing cooling demand and heating demand.

Cooling Demand
1. Prompt a cooling demand at the thermostat.
2. Press the Test button on the RDS Blower Control Board.
The system then executes a refrigerant detection response.
3. Observe the following sequence:
a. The LED indicator flashes the sequence for refrigerant detection (flashing blue).
b. The blower powers up. c. The outdoor compressor powers down. 4. Press the Test button to terminate the
simulated Refrigerant Detected mode upon test completion.
Heating Demand
1. Prompt a heating demand at the thermostat.
2. Press the Test button on the RDS Blower Control Board.
The system then executes a refrigerant detection response.
3. Observe the following sequence:
a. The LED indicator flashes the sequence for refrigerant detection (flashing blue).
b. The blower powers up. c. The gas burners power down. d. The outdoor compressor powers down.

4. Press the Test button to terminate the simulated Refrigerant Detected mode upon test completion.
The installation of the RDS Blower Control Board is complete after both sequences are successfully completed.
18

Wiring Diagrams
Lennox provides wires designated for wiring the sensor cable. Wires required for the RDS installation is field supplied. The RDS supports all OEM and non-OEM gas furnace installations. Wiring diagrams are provided for several common split furnace system configurations to identify exact wire types and terminal locations.
Communicating Indoor Controls and Float Switch
Lennox Communicating Furnace Unit
For Float Switch Operation, Cut R-DS

Cut R-DS W914

Float Switch

Communicating Thermostat with Furnace and Outdoor Units

RDS Sensor

1 W1

SW2 SENSOR #1 SENSOR #2

W2
ON
G LED

1 Thermostat / Outdoor Unit Terminal Block (BLACK)

SW1

RDS Field Kit Communicang

Cat # 27A03

2 Indoor Unit Terminal Block (BLUE) 3 Communicang Thermostat Terminal Block (BLACK) 4 Communicang Indoor Unit / Equipment Terminal Block (BLUE)

TSTAT

ZONING ALARM

INDOOR

R I+ I- C NO COM NC NO COM NC R I+ I- C

Communicang Outdoor Unit
R I+ I- C

R I+ I- C Communicang Thermostat

R I+ I- C

Communicang Furnace

Communicating Thermostat, Communicating Furnace with EIM, and Non-Communicating Two Stage Heat Pump

RDS Sensor

W1 1

SW2 SENSOR #1 SENSOR #2 2 W1

G LED

SW1

RDS Field Kit Communicang

Cat # 27A03

TSTAT R
3

I+ I- C

ZONING ALARM

INDOOR

NO COM NC NO COM NC R I+ I- C

HP IFC AHC

R I+ I- C

0 1 2 3
UNIT TYPE HEAT STAGES OAS P3

HEAT PUMP SIZE

OUTDOOR DISCHARGE AIR SENSOR AIR SENS0OR

W1 O B DEF DFTS

P5
Equipment Interface Module (EIM) CAT # 22X18
OTHERS O N
VENT
P4
VENT VENT VENT 12 3
P1 W1 W2 W3 G Y2 Y1 C DS R H O B P2 F1

1.5 2.0 2.5 3.0 3.5 4.0 5.0

R I+ I- C Communicang Thermostat

R I+ I- C

Communicang Furnace

Y2 Y1 C

O W1

Two Stage Heat Pump

1 Thermostat / Outdoor Unit Terminal Block (BLACK) 2 Indoor Unit Terminal Block (BLUE) 3 Communicang Thermostat Terminal Block (BLACK) 4 Communicang Indoor Unit / Equipment Terminal Block (BLUE)

Communicating Thermostat, Non-Communicating Two Stage Furnace with EIM, and Communicating Outdoor Unit

1.5 2.0 2.5 3.0 3.5 4.0 5.0

HP IFC AHC

R I+ I- C

0 1 2 3
UNIT TYPE HEAT STAGES HEAT PUMP SIZE OAS P3

OUTDOOR DISCHARGE AIR SENSOR AIR SENS0OR

W1 O B DEF DFTS

OTHERS O N

Equipment Interface Module (EIM) CAT # 22X18

VENT
P4

VENT VENT VENT 12 3
P1 W1 W2 W3 G

Y2 Y1

C DS R H

O B P2 F1

1 Thermostat / Outdoor Unit Terminal Block (BLACK) 2 Indoor Unit Terminal Block (BLUE) 3 Communicang Thermostat Terminal Block (BLACK) 4 Communicang Indoor Unit / Equipment Terminal Block (BLUE)

RDS Sensor

W1 1 W2 G LED Y2 Y1 C R DH H

SW2 SENSOR #1 SENSOR #2 ON SW1
RDS Field Kit Communicang Cat # 27A03

L O

TSTAT R
3

I+ I- C

ZONING ALARM NO COM NC NO COM NC R

2 W1

Gas Furnace

Two Stage

INDOOR

I+ I- C

Communicang

R I+ I- C

Thermostat

OPTIONAL ISOLATION RELAY WITH N.C. CONDENSATE FLOAT SWITCH

Communicang Outdoor Unit
R I+ I- C

Non-Communicating Thermostat, Communicating Two Stage Furnace with Non-Communicating Two Stage Outdoor Unit

Thermostat
W1 W2
G Y2 Y1 C R
OPTIONAL N.C. CONDENSATE
FLOAT SWITCH Two Stage Outdoor Unit
Y2 Blue Y1 Yellow
Black C

RDS Sensor

1 W1

SW2 SENSOR #1 SENSOR #2

G LED

SW1

RDS Field Kit Communicang

Cat # 27A03

TSTAT R
3

I+ I- C

ZONING ALARM

INDOOR

NO COM NC NO COM NC R I+ I- C

W1 W2 G Y2 Y1 C R
R I+ IC
Communicang Furnace W/ Convenonal T-Stat

1 Thermostat / Outdoor Unit Terminal Block (BLACK) 2 Indoor Unit Terminal Block (BLUE)

3 Communicang Thermostat Terminal Block (BLACK) 4 Communicang Indoor Unit / Equipment Terminal Block (BLUE)

Communicating Thermostat with Communicating Furnace and Non-Communicating Two Stage Outdoor Units
RDS Sensor

W1 W2 G LED Y2 Y1 C R DH H L O

SW2 SENSOR #1 SENSOR #2 ON SW1
RDS Field Kit Communicang Cat # 27A03

TSTAT

ZONING ALARM

R I+ I- C NO COM NC NO COM NC R

2
W1 W2
G Y2 Y1
C R DH H L O DS INDOOR I+ I- C
4

R I+ I- C Communicang Thermostat

Communicang Furnace
W1 W2 G Y2 Y1 C R
C II+ R
Black C
Yellow Y1 Blue Y2
Two Stage Outdoor Unit

1 Thermostat / Outdoor Unit Terminal Block (BLACK) 2 Indoor Unit Terminal Block (BLUE) 3 Communicang Thermostat Terminal Block (BLACK) 4 Communicang Indoor Unit / Equipment Terminal Block (BLUE)

In- Zone Stat Damper

Communicating Zoning with Communicating Thermostat, Communicating Indoor and Outdoor Units

RDS Sensor

W1 1 W2 G LED Y2 Y1 C R DH H L O DS TSTAT R I+ I- C 3

SW2 SENSOR #1

2 W1

G
SW1
Y2

RDSC Field Kit Communicang

Cat # 27A03

L O

ZONING ALARM

INDOOR

NO COM NC NO COM NC R I+ I- C

DATS

DMPR XFMR

C SEN SEN 24 SEN 24 SENSE 24 R C

DATS PS

R i+ i- C Indoor

PWR D+ DC
PWR D+ DC
PWR D+ DC
PWR D+ DC

ZONE 4/8

ZONE 3/7

ZONE 2/6

ZONE 1/5

DMPR SYS XFMR XFMR
3 3 AMP FUSE
Lennox Smart Zoning Control Module CAT# (10C16)

3/7 DAMPER 4/8 DAMPER

1/5 DAMPER 2/6 DAMPER

NC NO DCOM NC NO DCOM
NC NO DCOM NC NO DCOM

R I+ I- C Communicang Thermostat

R I+ I- C

Communicang Indoor Unit

R I+ I- C Communicang Outdoor Unit

1 Thermostat / Outdoor Unit Terminal Block (BLACK) 2 Indoor Unit Terminal Block (BLUE) 3 Communicang Thermostat Terminal Block (BLACK) 4 Communicang Indoor Unit / Equipment Terminal Block (BLUE)

Diagnostic Codes and Troubleshooting

Table 6. LED Diagnostic Codes

State

LED Diagnostic Code

Action Required

Initializing

Flashing green

Monitoring
Mitigating (Refrigerant Detected)
Fault/Service

Solid green. If a prior mitigation occurred, a blue flash interrupts the solid
green LED.
Flashing blue
Solid blue, interrupted by issue diagnostic code

None
None
Check coil tubes for refrigerant. Repair the issue and restart the equipment. Refer to Table 7 for troubleshooting steps.

Red Flash 1 2 3
4

Table 7. Red LED Diagnostic Codes / Troubleshooting

Applies to Individual Sensor(s) Yes No Yes
Yes

Issue
Sensor indicates fault Spare Code - Unused Incompatible sensor type
Sensor communications issue

Action Required
Replace the sensor (Cat. # 27V53) Not Applicable
Replace the sensor (Cat. # 26Z69)
· Verify sensor DIP switch settings are correct.
· Verify sensor connection is secure.
· Ensure connection is clean and free of debris.

Red Flash 5 6

Table 7. Red LED Diagnostic Codes / Troubleshooting

Applies to Individual Sensor(s)
No
No

Issue

Action Required

Indoor unit wiring incorrectly connected to the "Black TSTAT" terminal strip on the RDS
control.

· Check wiring connections.
· Ensure the indoor unit is wired to the "Blue INDOOR" terminal strip.
· Verify the Room Thermostat is wired to the "Black TSTAT" terminal strip.

Invalid configuration of sensor count

Verify the DIP switch setting is correct and matches the number of sensors being used.

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