White Rodgers 50M56U-843 User Manual

PAGE 3 CONTAINS WIRING HARNESS AND
BLOWER CONNECTION INSTRUCTIONS FOR
ALL APPLICATIONS AND IMPORTANT OEM
REPLACEMENT INSTRUCTION FOR:
● TRANE / AMERICAN STANDARD
● RHEEM / RUUD
● BRYANT / CARRIER / DAY & NIGHT / PAYNE
INSTALLER MUST READ
www.white-rodgers.com
www.emersonclimate.com
50M56U-843
Universal Single Stage
HSI Integrated Furnace Control Kit
INSTALLATION INSTRUCTIONS
FAILURE TO READ AND FOLLOW ALL INSTRUCTIONS
CAREFULLY BEFORE INSTALLING OR OPERATING
THIS CONTROL COULD CAUSE PERSONAL INJURY
AND/OR PROPERTY DAMAGE.
DESCRIPTION
The 50M56U-843 kit is a Universal Single Stage HSI Integrated
Furnace Control that employs a microprocessor to continually
monitor, analyze, and control the proper operation of the gas
burner, inducer, and fan.
The kit contains:
• 50M56-843IgnitionControlModule
• 21D64-2IgnitorKit
• SetofInterconnectHarnesses
Installation should be done by a qualified heating and air
conditioning contractor or licensed electrician.
If in doubt about whether your wiring is millivolt, line, or low
voltage, have it inspected by a qualified heating and air
conditioning contractor or licensed electrician.
Donotexceedthespecicationratings.
All wiring must conform to local and national electrical codes
and ordinances.
This control is a precision instrument, and should be handled
carefully. Rough handling or distorting components could
cause the control to malfunction.
Following installation or replacement, follow manufacturer’s
recommended installation/service instructions to ensure
proper operation.
PRECAUTIONS
PART NO. 37-7042C
Replaces37-7042B
1103
Do not short out terminals on gas valve or primary
control. Short or incorrect wiring may damage the
thermostat.
CAUTION
!
Failure to comply with the following warnings could result
in personal injury or property damage.
FIRE HAZARD
• Donotexceedthespeciedvoltage.
• Replaceexistingcontrolwithexactmodeland
dash number.
• Protectthecontrolfromdirectcontactwithwater
(dripping, spraying, rain, etc.).
• Ifthecontrolhasbeenindirectcontactwith
water, replace the control.
• Labelallwiresbeforedisconnectionwhen
servicing controls. Wiring errors can cause
improper and dangerous operation.
• Routeandsecurewiringawayfromame.
SHOCK HAZARD
• Disconnectelectricpowerbeforeservicing.
• Ensureproperearthgroundingofappliance.
• Ensureproperconnectionoflineneutralandline
hot wires.
EXPLOSION HAZARD
• Shutoffmaingastoapplianceuntilinstallation
is complete.
WARNING
!
CONTENTS
Description ...................................................................1
Precautions ..................................................................1
Specifications ..............................................................2
Installation ...................................................................2
Mounting & Wiring
Operation ..................................................................... 6
Troubleshooting ........................................................... 8
50M56-843
21D64-2

White Rodgers 50M56U-843 Specifications

General

Type	Integrated Furnace Control
Voltage	24 VAC
Ignition Type	Hot Surface Ignition
Replaces	50M56-843, 50M56U-843
Compatible Furnace Types	Single stage
Safety Features	pressure switch monitoring
Operating Temperature Range	-40°F to 176°F (-40°C to 80°C)

Summary

Installer Must Read

Product Overview and Precautions

Description

Details the control's function, components, and kit contents.

Precautions

Essential safety warnings for installation and operation to prevent injury or damage.

Specifications

Installation

Mounting and Wiring

Details mounting procedures and wiring requirements for the control.

Important OEM Replacement Instructions

Specific instructions for replacing controls in certain OEM furnace models.

Wiring Diagrams

Typical System Wiring Diagram

Illustrates the typical system wiring connections for the control.

Typical System Wiring Table

Lists terminals and their corresponding system component connections.

Operation

Option Switches

Explains how option switches determine control operation modes and delays.

Heat Mode

Describes the heating sequence, ignitor operation, and fan control.

Cool Mode

Explains the cooling sequence, including compressor and fan control.

System Lockout and Diagnostic Features

Covers system lockout conditions and how to reset the control.

Diagnostic Features

Fault Code Reset

Instructions for clearing stored fault codes from the control's memory.

Fault Recall

How to display previously stored failure codes using the diagnostic LED.

Definition of Terms

Glossary of terms used in the operation and troubleshooting sections.

Troubleshooting

Red LED Flash Codes

Lists error conditions indicated by red LED flash codes.

Rapid Flash

Indicates reversed polarity error.

Continuous On

Indicates normal operation status.

Off

Indicates a control failure.