Raypak boiler error codes

Modern gas boilers have microchip-based adjustment and control systems. They detect malfunctions and display error codes on the screen, which denote faults occurring in the boiler’s units. Boilers’ control systems react differently to faults, depending on the possible consequences:

  • Emergency shutoff is activated and blocks the boiler’s work immediately. To clear the error, restart the boiler by pressing the Reset button. Thus you will restore the boiler to factory default settings.
  • Emergency shutoff is activated, but the boiler is not blocked. When the error is cleared, the boiler will get back to work with all user settings intact.
  • There are warning codes, which do not require immediate interference and do not stop the boiler.

AL10Ignition failure/not flame sensed, condense sensor activatedReset, check appliance operation
AL20Limit thermostat fault, blocked flue switch, flue thermostat
AL21External device fault (UHT/CPA)Reset, check appliance
AL26Return temperature too highReset, check pump, ensure there is sufficient flow sensor temperature). Circulation around heating circuit/s
AL28Temperature differential inverted (return sensor temperature higher than flowsensor temperature)Reset, check pump, ensure there is sufficient circulation around heating circuit/s thermistors
AL29Flue sensor over temperature lock outReset check appliance operation
AL34Fan blower signal faultReset check appliance operation, check fan
AL40Insufficient system water pressureCheck/refill system pressure, reset, check
AL41Insufficient system water pressureCheck/refill system pressure, check appliance operation
AL52Internal faultReset, check boiler operation
AL55Jumper tag faultCheck jumper tag configuration
AL60Jumper tag fault
AL71Primary (flow) sensor faultCheck primary thermistor, check wiring
AL73Return sensor faultCheck return thermistor, check /wiring
AL74Variation on temperature of primaryReset, check boiler operation, check and/or return too high pump, ensure there is sufficient circulation around heating circuit/s
AL79Flow temperature too high, or temperature differential between Drimarv and return too hiqhReset, check appliance operation, check thermistors
AL91The main heat exchanger need to be cleanedCall the Raypak technical service