Diagnostic Codes And Part Numbers - Hayward H150FDN Troubleshooting Manual

Below is a list of all Diagnostic Codes for the UHS Heater. Troubleshooting Steps for
Diagnostic
Code
AC
AO
BD
CE
EE
HF
HS
IF
IO
LO
PF
SB
SF
19
Diagnostic Codes
each Code are covered on the following pages.
Blower Vacuum Switch closed
Blower Vacuum Switch open
Bad board or secondary high voltage fault
Communication Error Between Control Module and Display Interface Assembly
Bad board
Flame present with Gas Valve not energized.
Maximum return water temperature exceeded and / or rapid water temperature rise.
Ignition Failure
Ignitor Circuit Open
Water Pressure Switch, Vent Pressure Switch, or Temperature Limit Switch Fault
Voltage polarity reversed, low voltage detected
Keypad failure
Temperature Sensor (thermistor) input failure
Description