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Hayward Poolheater Error Codes

All Hayward poolheater error codes with step-by-step troubleshooting, multimeter specs, and OEM part numbers.

10 error codes

CodeMeaning
10The heater failed to establish or sustain a flame after multiple ignition attempts and has entered a hard lockout.
highintermediate
A1The water temperature sensor (thermostat sensor) is reading outside its valid range, indicating a failed sensor, a wiring fault, or actual water temperature outside operating limits.
moderateintermediate
AOThe combustion air pressure switch did not close during startup, indicating insufficient combustion air flow or a restricted vent.
highintermediate
BDA blower drain or combustion air pressure fault, most commonly caused by a blocked condensate drain on condensing H-Series models or a combustion air pressure switch fault.
moderateintermediate
BOThe combustion blower motor or combustion chamber has exceeded safe temperature limits, triggering the thermal overheat safety lockout.
highintermediate
CEA communication failure between the heater control board and the display panel, remote controller, or pool automation system.
moderateadvanced
HUBReference guide covering all Hayward H-Series pool heater error codes and fault indicators.
lowbeginner
IFIgnition Failure - the heater attempted to light the burner multiple times and could not establish or hold a flame.
highintermediate
LOWater flow through the heater has fallen below the minimum required threshold, triggering a safety lockout to protect the heat exchanger.
highbeginner
NOT-HEATINGLO, HI, IF, and Bypass Valve Fixes
mediumintermediate