Carrier PG9UAA - User Manual

1
PG9UAA
Troubleshooting Guide
VARIABLE SPEED, TWO---STAGE
ELECTRONIC CONDENSING
GAS FURNACE
INDEX
PAGE
SAFETY CONSIDERATIONS 1..................................................
INSTRUCTIONS 1............................................................
EXAMPLE 2.................................................................
GENERAL 2.................................................................
SEQUENCE OF OPERATION 2..................................................
Single--Stage Thermostat and Two--Stage Heating (Adaptive Mode) 2...............
Two--Stage Thermostat and Two--Stage Heating 3..............................
Cooling Mode 4........................................................
Single--Speed Cooling 4..................................................
Single--Stage Thermostat and Two--Speed Cooling (Adaptive Mode) 4..............
Two--Stage Thermostat and Two--Speed Cooling 4.............................
Dehumidify Mode 4.....................................................
Super--Dehumidify Mode 5...............................................
Continuous--Blower Mode 5..............................................
Heat Pump Defrost 5....................................................
Component Test 5......................................................
SERVICE/STATUS CODE INSTRUCTIONS 6.......................................
START HERE 8...............................................................
RAPID FLASHING AMBER LED 9...............................................
IMPROPER COOLING AIR FLOW 10.............................................
HIGH HEAT TEMPERATURE RISE TOO LOW 11...................................
STATUS CODE 11 -- NO PREVIOUS CODE 12......................................
STATUS CODE 12 -- BLOWER ON AFTER POWER UP 12............................
STATUS CODE 13 -- LIMIT CIRCUIT LOCKOUT 13.................................
STATUS CODE 14 -- IGNITION LOCKOUT 14......................................
STATUS CODE 15 – BLOWER MOTOR LOCKOUT 14...............................
STATUS CODE 21 -- GAS HEATING LOCKOUT 14..................................
STATUS CODE 22 -- ABNORMAL FLAME--PROVING SIGNAL 15.....................
STATUS CODE 23 -- PRESSURE SWITCH DID NOT OPEN 15.........................
STATUS CODE 24 -- SECONDARY VOLTAGE FUSE IS OPEN 16.......................
STATUS CODE 25 – MODEL SELECTION OR SETUP ERROR 18......................
STATUS CODE 31 – HIGH--HEAT SWITCH OR RELAY DID NOT CLOSE OR REOPEN 18..
STATUS CODE 32 -- LOW--HEAT PRESSURE SWITCH DID NOT CLOSE OR
REOPENED 20...............................................................
STATUS CODE 33 -- LIMIT CIRCUIT FAULT 22....................................
STATUS CODE 34 -- IGNITION--PROVING FAULT 24................................
STATUS CODE 41 – BLOWER MOTOR FAULT 25..................................
STATUS CODE 42 – INDUCER MOTOR FAULT 27..................................
STATUS CODE 43 -- LOW--HEAT PRESSURE SWITCH OPEN WHILE HIGH--HEAT
PRESSURE SWITCH IS CLOSED 29..............................................
STATUS CODE 45 – CONTROL CIRCUITRY LOCKOUT 30...........................
CLEANUP AND START--UP INSTRUCTIONS 30....................................
APPENDIX A -- BOARD LAYOUT & WIRING SCHEMATIC 31........................
APPENDIX B -- ECM BLOWER MOTOR DESCRIPTION & OPERATION 33..............
APPENDIX C -- PRESSURE CHECK DIAGRAM 34..................................
APPENDIX D -- STATIC PRESSURE READING LOCATION DIAGRAMS 35..............
APPENDIX E -- QUICK REFERENCE INFORMATION 36.............................
APPENDIX F -- FURNACE STAGING ALGORITHM 37...............................
SAFETY CONSIDERATIONS
Installing and servicing heating equipment can be hazardous due to
gas and electrical components. Only trained and qualified
personnel should install, repair, or service heating equipment.
Untrained personnel can perform basic maintenance functions such
as cleaning coils, or cleaning and replacing filters. All other
operations should be performed by trained service personnel.
When working on heating equipment, observe precautions in
literature, on tags, and on labels attached to or shipped with the
unit, and other safety precautions that may apply.
Follow all safety codes. In the United States, follow all safety
codes including the National Fuel Gas Code (NFGC) NFPA
54--2009/ANSI Z223.1--2009. In Canada, refer to the National
Standard of Canada Natural Gas and Propane Installation Codes
(NSCNGPIC), CSA B149.1--10.
Wear safety glasses and work gloves. Have a fire extinguisher
available during start--up, adjustment procedures, and service calls.
Recognize safety information. This is the safety--alert symbol
.
When you see this symbol on the furnace and in instructions or
manuals, be alert to the potential for personal injury.
Understand the signal words DANGER, WARNING, and
CAUTION, and NOTE. The words DANGER, WARNING, and
CAUTION are used with the safety--alert symbol. DANGER
identifies the most serious hazards which will result in severe
personal injury or death. WARNING signifies hazards which
could result in personal injury or death. CAUTION is used to
identify unsafe practices which may result in minor personal injury,
or product and property damage. NOTE is used to highlight
suggestions which will result in enhanced installation, reliability, or
operation.
INSTRUCTIONS
This guide uses your expertise and observations to lead you to the
trouble spot as efficiently as possible. This is only intended as a
guide and should not be used blindly. Your experience and
expertise are of high value when troubleshooting this unit. Do not
disregard all of your instincts.
The variable speed furnace control was designed with diagnostic
capabilities built in. An AMBER LED is used to flash a status
code which will lead you to one of the sections as listed in the
Index.
You should ALWAYS begin in the START HERE section (see
Index for page number) which will guide you to the appropriate
section where a minimal number of steps will be used to correct the
problem. Once in a section, read the ACTION. An ACTION may
have a number in the GO TO column. Do whatever the ACTION
says, then proceed to the step indicated in the GO TO column.
If the ACTION is a question (a question will have a number in the
YES or NO column), answer it YES or NO. If the answer is YES,
go to the step indicated in the YES column. If the answer is NO,
go to the step indicated in the NO column.

Summary

SAFETY CONSIDERATIONS

General Safety Precautions

General safety precautions for installing and servicing heating equipment.

Signal Words and Safety-Alert Symbol

Explains the safety-alert symbol and signal words like DANGER, WARNING, and CAUTION.

INSTRUCTIONS

How to Use This Troubleshooting Guide

Guide on using the manual effectively and understanding its diagnostic capabilities.

Example Troubleshooting Walkthrough

Demonstrates how to use the guide by following a step-by-step example.

SEQUENCE OF OPERATION

Single-Stage Thermostat and Two-Stage Heating (Adaptive Mode)

Details operation with a single-stage thermostat in adaptive two-stage heating mode.

Two-Stage Thermostat and Two-Stage Heating

Details operation with a two-stage thermostat in two-stage heating mode.

Single-Stage Thermostat and Two-Speed Cooling (Adaptive Mode)

Two-Stage Thermostat and Two-Speed Cooling

COMPONENT TEST

Component Test Procedure

SERVICE;STATUS CODE INSTRUCTIONS

LED Status Indicators

Explains the meaning of different LED codes (Continuous Off, Continuous On, Rapid Flashing).

General Status Code Structure

Defines status codes as two-digit numbers based on short and long flashes.

Common Status Codes and Their Meanings

Lists and describes common status codes like 11 through 45, detailing their causes and troubleshooting steps.

START HERE

Troubleshooting Entry Point

The primary section for initiating furnace troubleshooting procedures.

Step-by-Step Troubleshooting Flow

Follows a step-by-step process to diagnose furnace problems based on LED status.

RAPID FLASHING AMBER LED

Troubleshooting Rapid Flashing LED

Steps to diagnose a rapid flashing amber LED, indicating reversed line voltage polarity or phase issues.

IMPROPER COOLING AIR FLOW

Diagnosing Improper Cooling Airflow

Troubleshooting steps for issues related to insufficient or improper cooling airflow.

HIGH HEAT TEMPERATURE RISE TOO LOW

Diagnosing High Heat Temperature Rise Too Low

Identifies issues when the high heat temperature rise is too low, often due to the gas valve.

Status Code 31

Status Code 31: High-Heat Pressure Switch or Relay Did Not Close or Reopened

Status Code 32

Status Code 32: Low-Heat Pressure Switch Did Not Close or Reopened

Status Code 43

Status Code 43: Low-Heat Pressure Switch Open While High-Heat Pressure Switch Is Closed

APPENDIX A BOARD LAYOUT & WIRING SCHEMATICS

Board Layout Diagram

Wiring Schematic Overview

APPENDIX B ECM BLOWER MOTOR DESCRIPTION & OPERATION

ECM Blower Motor Operation

Explains the functionality and programming of the Electronically Commutated Motor (ECM) blower.

APPENDIX C PRESSURE CHECK DIAGRAM

Pressure Switch Make;Break Points

Table detailing the pressure switch make and break points for different unit sizes.

Pressure Check Diagram

APPENDIX D STATIC PRESSURE READING LOCATION DIAGRAMS

Static Pressure Reading Locations

APPENDIX E QUICK REFERENCE INFORMATION

Pressure Switch Specifications

Quick reference table for high and low heat pressure switch make/break points.

Flame Sensor and Igniter Readings

APPENDIX F FURNACE STAGING ALGORITHM

Furnace Staging Algorithm Explained

Details how the furnace staging algorithm determines heating stages based on past performance.

Staging Algorithm Calculation Flowchart

Visual flowchart illustrating the furnace staging algorithm's calculations for heat cycles.

Carrier PG9UAA Specifications

General

Model	PG9UAA
Heating Capacity	40, 000-120, 000 BTU/h
Stages	2-Stage
Blower Type	Variable-speed
Fuel Type	Natural Gas/Propane
Warranty	10-Year Parts Limited Warranty upon registration