Equipment guide
Pool Heater error codes
Codes are manufacturer-specific. Choose the exact brand shown on your equipment.
Official Hayward material describes AC as Blower vacuum switch closed when expected open; if the switch is closed before blower start-up, the control will not start the blower. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Hayward material describes AO as The blower prover switch does not close after the blower starts; the control stops the ignition trial and goes into lockout with the blower continuing to run. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Hayward material describes bD as Internal fault/power-up error. Shown on the initial trial for ignition. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Hayward material describes CE as Communication error: communication between the ignition board and the display board is not established within 3 seconds of power-up, or is lost for 30 seconds after being established. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Hayward material describes EE as EEPROM error: an error was detected in the ignition control circuit board. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Hayward material describes HF as Flame present with the gas valve OFF; the control goes into lockout and the blower runs until the error condition is corrected. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Hayward material describes HS as Water temperature sensing error: (A) the inlet water temperature sensor reports a temperature in excess of 104 degrees F; normal operation resumes 2 minutes after the sensor reports 104 degrees F or less. Or (B) the inlet sensor reports a temperature change faster than 6 degrees F in 60 seconds, indicating a…
Official Hayward material describes IF as Ignition failure: the control exceeded the maximum number of ignition retries or recycles; the heater shuts down and goes into lockout. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Hayward material describes IO as Igniter open error: the igniter circuit is sensed open while the blower is running (when not in lockout); the control turns off the blower and goes into lockout. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Hayward material describes LO as Limit string open error: if the limit string opens, the heater shuts down and goes into lockout. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Hayward material describes PF as Electrical supply wiring error: displays if 120V polarity is reversed, low voltage is detected, or the ground path is not sufficient. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Hayward material describes Sb as Keypad button stuck closed: one of the keypad buttons is closed (or pressed) for more than 30 seconds; the error code displays but the control continues to function. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Hayward material describes SF as Thermistor error: an excessive temperature difference between the two thermistors (5 degrees F or more), or an 'out of bounds' condition on both sensors (less than 10 degrees F or greater than 180 degrees F). This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Pentair material describes 126 as Shorted water temperature sensor. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Pentair material describes E01 as Open water temperature sensor. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Pentair material describes E05 as Open stack flue sensor. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Pentair material describes E06 as Shorted stack flue sensor. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Pentair material describes ERR AFS as Air flow switch open: the blower is not on, or air through it is being restricted. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Pentair material describes ERR AGS as Automatic gas shutoff: water temperature after the second pass through the heat exchanger is more than 140 degrees F. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Pentair material describes ERR HLS as Hi temperature limit switch open: water temperature after the first pass through the heater exchanger is more than 135 degrees F. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Pentair material describes ERR IGN as Ignition Control Module was not able to ignite the heater. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Pentair material describes ERR PS as Water pressure switch open: no water flow through the heater. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.
Official Pentair material describes ERR SFS as Excessive stack flue temperature: the temperature of the stack flue is more than 480 degrees F. This guide records the cited product-family scope, safety-reviewed owner checks, and service limits.