Residential Fan Coil Units
Service Manual
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 ..................................................................4
CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING
— HK61GA001 and HK61GA003 PCB .........................6-19
• Printed Circuit Board Component Layout and Description.......6
• PCB Component Functions.........................................................7
• Troubleshooting PCB ................................................................11
ELECTRIC HEATER FUNCTION
AND TROUBLESHOOTING..............................................18
• 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 ................................................................25
• Troubleshooting ICM2 ..............................................................25
• Condensed Version of Troubleshooting FK4B Motor
and Controls ...............................................................................27
• Accessories ................................................................................27
FAN COIL DESCRIPTION AND
TROUBLESHOOTING — FK4C, FV4A, 40FKA .........28-35
• Integrated Controls and Motor (ICM2) ..................................28
• PCB Layout and Description ..................................................29
• Sequence of Operation ............................................................29
• Easy Select Configuration Taps..............................................32
• Troubleshooting PCB ..............................................................33
• Troubleshooting ICM2 ............................................................33
• Condensed Version of Troubleshooting
FK4C, FV4A, 40FKA Motor and Controls.........................33
• Accessories ..............................................................................35
THERMOSTATIC EXPANSION VALVES (TXV) ............36
• Problems Affecting TXV ........................................................36
PISTON BODY CLEANING OR REPLACEMENT..........36
LIQUID TUBE STRAINER ...................................................37
FA, FB, FC, FK COIL/CONDENSATE PAN
REMOVAL AND REPLACEMENT ..........................37-38
• A-Coil Units ............................................................................37
• Slope Coil Units ......................................................................37
FX, FV, 40FKA COIL/CONDENSATE PAN REMOVAL
AND REPLACEMENT ................................................38-40
CARE AND MAINTENANCE...............................................39
• Filter Assembly .......................................................................39
• Cooling Coil, Drain Pan, and Condensate Drain ...................39
• Blower Motor and Wheel .......................................................40
FF1A/FF1B/FF1C SERVICE AND
TROUBLESHOOTING ................................................40-42
• Fan Motor ................................................................................40
• Electric Heater Service............................................................40
• Cleaning or Replacing Refrigerant Flow-Control Device .....42
• Liquid Tube Strainer ...............................................................42
• Sequence of Operation ............................................................42
• Care and Maintenance.............................................................42
FD3A SERVICE AND TROUBLESHOOTING...............43-45
• Fan Motor ..................................................................................43
• Electric Heater Service..............................................................43
• Cleaning or Replacing Refrigerant Flow-Control Device .......43
• Liquid Tube Strainer .................................................................45
• Care and Maintenance...............................................................45
FG3A SERVICE AND TROUBLESHOOTING ....................46
• Service .......................................................................................46
• Maintenance...............................................................................46
FA4A, FB4A, FC4B, FX4A SMART HEAT CIRCUIT
BOARD FUNCTION AND TROUBLESHOOTING..46-50
• PCB Component Layout, Description, and Function...............46
• Unit Functions ...........................................................................47
• Smart Heat Operation................................................................48
• Electrical Operating Sequences and Troubleshooting..............48
PURON® (R-410A) QUICK REFERENCE GUIDE.............51
Fig. 1—Typical Fan Coil
A98023
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Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1
4
Tab
3d 2e
PC 101
Catalog No. 03FA-4A3
Printed in U.S.A.
Form F-5SM
Pg 1
6-99
Replaces: F-4SM
