TABLE OF CONTENTS
Page
SAFETY CONSIDERATIONS...................................................2
INTRODUCTION ........................................................................2
UNIT IDENTIFICATION...........................................................2
PRODUCT OFFERING ..............................................................4
FAN MOTOR SPEED TAPS .....................................................4
FA4A, FB4A, FC4B, FF1D, FH4A, AND FX4A
CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING
— CES013003-00 and -01 PCB...............................................2-7
• Printed Circuit Board Component Layout and Description.......2
• Unit Functions ............................................................................2
• Troubleshooting PCB ..................................................................5
CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING
— HK61GA001 and HK61GA003 PCB .........................8-19
• Printed Circuit Board Component Layout and Description.......8
• PCB Component Functions.........................................................9
• Troubleshooting PCB ................................................................11
ELECTRIC HEATER FUNCTION
AND TROUBLESHOOTING..............................................19
• Description of Electric Heater Components.............................19
• Troubleshooting KFA, KFB, KFC, and KFD Series
Electric Heaters.......................................................................20
FAN COIL DESCRIPTION
AND TROUBLESHOOTING — FK4B .......................20-27
• Integrated Controls and Motor (ICM2) ....................................20
• PCB Layout and Description ....................................................20
• Sequence of Operation ..............................................................21
• Easy Select Configuration Taps................................................22
• Troubleshooting PCB ................................................................24
• Troubleshooting ICM2 ..............................................................26
• Condensed Version of Troubleshooting FK4B Motor
and Controls ...............................................................................26
• Accessories ................................................................................27
FAN COIL DESCRIPTION
AND TROUBLESHOOTING — FK4C, FV4A...........28-34
• Integrated Controls and Motor (ICM2) ....................................28
• PCB Layout and Description ....................................................28
• Sequence of Operation ..............................................................28
• Easy Select Configuration Taps................................................30
• Troubleshooting PCB ................................................................32
• Troubleshooting ICM2 ..............................................................34
• Condensed Version of Troubleshooting
FK4C, FV4A Motor and Controls .........................................34
• Accessories ................................................................................34
THERMOSTATIC EXPANSION VALVES (TXV) ..............35
• Problems Affecting TXV ..........................................................36
PISTON BODY CLEANING OR REPLACEMENT............36
LIQUID TUBE STRAINER .....................................................36
FA, FB, FC, FK COIL/CONDENSATE PAN
REMOVAL AND REPLACEMENT..................................36
• A-Coil Units ..............................................................................36
• Slope Coil Units ........................................................................37
FX, FV COIL/CONDENSATE PAN REMOVAL
AND REPLACEMENT........................................................38
CARE AND MAINTENANCE.................................................39
• Filter Assembly .........................................................................39
• Cooling Coil, Drain Pan, and Condensate Drain .....................39
• Blower Motor and Wheel .........................................................39
FF1A/FF1B/FF1C SERVICE AND
TROUBLESHOOTING ..................................................40-42
• Fan Motor ..................................................................................40
• Electric Heater Service..............................................................40
• Cleaning or Replacing Refrigerant Flow-Control Device .......40
• Liquid Tube Strainer .................................................................40
• Sequence of Operation ..............................................................40
• Care and Maintenance...............................................................40
FD3A SERVICE AND TROUBLESHOOTING...............44-45
• Fan Motor ..................................................................................44
• Electric Heater Service..............................................................44
• Cleaning or Replacing Refrigerant Flow-Control Device .......44
• Liquid Tube Strainer .................................................................44
• Care and Maintenance...............................................................45
FG3A SERVICE AND TROUBLESHOOTING...............45-46
• Service .......................................................................................45
• Maintenance...............................................................................46
FA4A, FB4A, FC4B, FX4A SMART HEAT CIRCUIT
BOARD FUNCTION AND TROUBLESHOOTING..46-50
• PCB Component Layout, Description, and Function...............46
• Unit Functions ...........................................................................46
• Smart Heat Operation................................................................47
• Electrical Operating Sequences and Troubleshooting..............48
PURON® (R-410A) QUICK REFERENCE GUIDE.............50
Fig. 1—Typical Fan Coil
A98023
Service Manual
RESIDENTIAL FAN COIL UNITS
Cancels:
SM03-4
SM03-5
6-99
—1—
