Jacuzzi Pool Heaters Error Codes
Complete list of fault codes and troubleshooting guides. Use the search below to find your specific error.
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AO
Jacuzzi pool heater shows AO; blower may run continuously even when there is no call for heat.
Airflow / Blower Overrun Fault
EO
Jacuzzi pool heater display is blank or shows EO; buttons may not respond.
Display / Keypad Failure
F1
Jacuzzi pool heater will not start; display shows F1 shortly after a call for heat.
Water Pressure Switch Open
F2
Jacuzzi pool heater ignites briefly then shuts down; display shows F2.
High Limit Switch Open (Overtemperature)
F3
Jacuzzi pool heater attempts to start but fails; display shows F3 and no flame is established.
Ignition Failure / Ignition Lockout
F4
Jacuzzi pool heater lights but then shuts down with F4 error; may cycle on and off frequently.
Flame Sense Failure / Flame Rectification Fault
F5
Jacuzzi pool heater display shows F5 and the unit will not fire; blower may run briefly then stop.
Air Pressure Switch / Combustion Air Proving Fault
F6
Jacuzzi pool heater shows F6 and shuts down; may occur during windy conditions or with long vent runs.
Flue Temperature / Vent Temperature Fault
F7
Jacuzzi pool heater display shows F7; heater will not respond to thermostat commands.
Thermostat / Temperature Sensor Fault
F8
Jacuzzi pool heater shows F8 and will not fire; may occur immediately on power-up.
Rollout Switch / Flame Rollout Fault
F9
Jacuzzi pool heater intermittently shuts down with F9; blower may continue to run.
Low Gas Pressure / Gas Supply Fault
FA
Jacuzzi pool heater display shows FA; heater may lock out until power is cycled.
Control Board Communication Fault
FC
Jacuzzi pool heater shows FC and will not respond to external controls (automation).
External Control / Communication Error
FS
Jacuzzi pool heater shows FS and may not maintain stable temperature.
Flow Switch / Flow Sensor Fault
HI
Jacuzzi pool heater display shows HI and shuts down; water may feel very hot at the outlet.
High Water Temperature / Overheat
LO
Jacuzzi pool heater display shows LO and the heater will not fire.
Low Water Temperature / Sensor Out of Range
SP
Jacuzzi pool heater display shows SP and the unit will not heat; often associated with spa mode or remote control.
Setpoint / Mode Conflict
Symptom
Jacuzzi pool heater blower runs but burners do not light; no error code displayed.
Silent Ignition Failure
Symptom
Jacuzzi pool heater causes the circuit breaker to trip when it starts or shortly after.
Overcurrent / Electrical Short
Symptom
Jacuzzi pool heater display and controls reset intermittently, especially when the blower or pump starts.
Control Voltage Drop / Electrical Interference
Symptom
Jacuzzi pool heater display shows normal operation but the gas meter shows unusually high consumption.
Excessive Gas Usage / Inefficiency
Symptom
Jacuzzi pool heater emits a strong chemical or burning smell during operation.
Overheating Components / Contaminants on Heat Exchanger
Symptom
Jacuzzi pool heater frequently locks out and requires manual reset, but no specific error code is stored.
Intermittent Safety Device Trip
Symptom
Jacuzzi pool heater heats the spa but not the pool, or vice versa, when using a shared system.
Incorrect Valve Position / Mode Control Issue
Symptom
Jacuzzi pool heater leaks water from the bottom of the cabinet.
Internal Water Leak
Symptom
Jacuzzi pool heater makes loud banging or popping noises during operation.
Heat Exchanger Kettling / Boiling
Symptom
Jacuzzi pool heater operates but the fan is excessively loud or makes grinding/squealing noises.
Blower Motor Bearing Wear / Fan Imbalance
Symptom
Jacuzzi pool heater produces visible soot or black staining around the exhaust outlet.
Sooting / Incomplete Combustion
Symptom
Jacuzzi pool heater responds slowly or not at all to button presses on the control panel.
Unresponsive Keypad
Symptom
Jacuzzi pool heater runs but does not heat the water; outlet water feels the same temperature as inlet.
No Heat Output
Symptom
Jacuzzi pool heater runs but water temperature overshoots the setpoint by several degrees.
Temperature Overshoot / Control Calibration Issue
Symptom
Jacuzzi pool heater short cycles: starts, heats briefly, then shuts off and restarts frequently.
Short Cycling / Inadequate Run Time
Symptom
Jacuzzi pool heater shuts down during heavy rain or after exposure to sprinklers.
Moisture Intrusion / Environmental Shutdown
Symptom
Jacuzzi pool heater starts normally but shuts off when the pump speed is reduced (variable-speed pump systems).
Low Flow at Reduced Pump Speed
Symptom
Jacuzzi pool heater will not start at all; no lights or display when power is turned on.
No Power / Dead Heater
| Error Code | Symptom | Fault Type | Guide |
|---|---|---|---|
| AO |
Jacuzzi pool heater shows AO; blower may run continuously even when there is no call for heat.
|
Airflow / Blower Overrun Fault | View Details |
| EO |
Jacuzzi pool heater display is blank or shows EO; buttons may not respond.
|
Display / Keypad Failure | View Details |
| F1 |
Jacuzzi pool heater will not start; display shows F1 shortly after a call for heat.
|
Water Pressure Switch Open | View Details |
| F2 |
Jacuzzi pool heater ignites briefly then shuts down; display shows F2.
|
High Limit Switch Open (Overtemperature) | View Details |
| F3 |
Jacuzzi pool heater attempts to start but fails; display shows F3 and no flame is established.
|
Ignition Failure / Ignition Lockout | View Details |
| F4 |
Jacuzzi pool heater lights but then shuts down with F4 error; may cycle on and off frequently.
|
Flame Sense Failure / Flame Rectification Fault | View Details |
| F5 |
Jacuzzi pool heater display shows F5 and the unit will not fire; blower may run briefly then stop.
|
Air Pressure Switch / Combustion Air Proving Fault | View Details |
| F6 |
Jacuzzi pool heater shows F6 and shuts down; may occur during windy conditions or with long vent runs.
|
Flue Temperature / Vent Temperature Fault | View Details |
| F7 |
Jacuzzi pool heater display shows F7; heater will not respond to thermostat commands.
|
Thermostat / Temperature Sensor Fault | View Details |
| F8 |
Jacuzzi pool heater shows F8 and will not fire; may occur immediately on power-up.
|
Rollout Switch / Flame Rollout Fault | View Details |
| F9 |
Jacuzzi pool heater intermittently shuts down with F9; blower may continue to run.
|
Low Gas Pressure / Gas Supply Fault | View Details |
| FA |
Jacuzzi pool heater display shows FA; heater may lock out until power is cycled.
|
Control Board Communication Fault | View Details |
| FC |
Jacuzzi pool heater shows FC and will not respond to external controls (automation).
|
External Control / Communication Error | View Details |
| FS |
Jacuzzi pool heater shows FS and may not maintain stable temperature.
|
Flow Switch / Flow Sensor Fault | View Details |
| HI |
Jacuzzi pool heater display shows HI and shuts down; water may feel very hot at the outlet.
|
High Water Temperature / Overheat | View Details |
| LO |
Jacuzzi pool heater display shows LO and the heater will not fire.
|
Low Water Temperature / Sensor Out of Range | View Details |
| SP |
Jacuzzi pool heater display shows SP and the unit will not heat; often associated with spa mode or remote control.
|
Setpoint / Mode Conflict | View Details |
| – |
Jacuzzi pool heater blower runs but burners do not light; no error code displayed.
|
Silent Ignition Failure | View Details |
| – |
Jacuzzi pool heater causes the circuit breaker to trip when it starts or shortly after.
|
Overcurrent / Electrical Short | View Details |
| – |
Jacuzzi pool heater display and controls reset intermittently, especially when the blower or pump starts.
|
Control Voltage Drop / Electrical Interference | View Details |
| – |
Jacuzzi pool heater display shows normal operation but the gas meter shows unusually high consumption.
|
Excessive Gas Usage / Inefficiency | View Details |
| – |
Jacuzzi pool heater emits a strong chemical or burning smell during operation.
|
Overheating Components / Contaminants on Heat Exchanger | View Details |
| – |
Jacuzzi pool heater frequently locks out and requires manual reset, but no specific error code is stored.
|
Intermittent Safety Device Trip | View Details |
| – |
Jacuzzi pool heater heats the spa but not the pool, or vice versa, when using a shared system.
|
Incorrect Valve Position / Mode Control Issue | View Details |
| – |
Jacuzzi pool heater leaks water from the bottom of the cabinet.
|
Internal Water Leak | View Details |
| – |
Jacuzzi pool heater makes loud banging or popping noises during operation.
|
Heat Exchanger Kettling / Boiling | View Details |
| – |
Jacuzzi pool heater operates but the fan is excessively loud or makes grinding/squealing noises.
|
Blower Motor Bearing Wear / Fan Imbalance | View Details |
| – |
Jacuzzi pool heater produces visible soot or black staining around the exhaust outlet.
|
Sooting / Incomplete Combustion | View Details |
| – |
Jacuzzi pool heater responds slowly or not at all to button presses on the control panel.
|
Unresponsive Keypad | View Details |
| – |
Jacuzzi pool heater runs but does not heat the water; outlet water feels the same temperature as inlet.
|
No Heat Output | View Details |
| – |
Jacuzzi pool heater runs but water temperature overshoots the setpoint by several degrees.
|
Temperature Overshoot / Control Calibration Issue | View Details |
| – |
Jacuzzi pool heater short cycles: starts, heats briefly, then shuts off and restarts frequently.
|
Short Cycling / Inadequate Run Time | View Details |
| – |
Jacuzzi pool heater shuts down during heavy rain or after exposure to sprinklers.
|
Moisture Intrusion / Environmental Shutdown | View Details |
| – |
Jacuzzi pool heater starts normally but shuts off when the pump speed is reduced (variable-speed pump systems).
|
Low Flow at Reduced Pump Speed | View Details |
| – |
Jacuzzi pool heater will not start at all; no lights or display when power is turned on.
|
No Power / Dead Heater | View Details |
No matching codes found
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