Ferroli Boiler Error Codes
The Ferroli range of powerful, boilers are normally extremely reliable. But things can still go wrong.
But in case things do go wrong, please find our handy at-a-glance table of all Ferroli error codes and repair advice below.
Should you need professional help with your broken boiler, then simply use one of our enquiry forms and we will connect you with the best heating engineers local to you.


Ferroli error codes
Listed below are some error codes that could appear on your Ferroli DOMIcondens HE 26 C, OPTIMAX HE PLUS 31C boiler or OPTIMAX HE PLUS 38C boiler.
Boilers | Fault Code | System Behaviour |
---|---|---|
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C | A01 | No burner ignition |
OPTIMAX HE PLUS 38C | A01 | The burner fails to light |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | A02 | Flame present signal with burner off, possible electrical fault |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | A03 | Over temperature protection activation |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C | A04 | Fume thermostat fault |
OPTIMAX HE PLUS 38C | A04 | Fume extraction duct safety device activation |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C | A05 | Fan fault or fume pressure switch fault |
OPTIMAX HE PLUS 38C | A05 | Fan protection activated |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | A06 | No flame after the ignition phase |
OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | F07 | High fume temperature |
DOMIcondens HE 26 C | F07 | Card parameter |
DOMIcondens HE 26 C | A09 | Gas value fault |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | F10 | Delivery sensor 1 fault |
DOMIcondens HE 26 C | F11 | DHW sensor fault |
OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | F11 | Return sensor fault |
OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | F13 | Fume sensor fault |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | F14 | Delivery sensor 2 fault |
OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | F15 | Fan fault |
DOMIcondens HE 26 C | A16 | Gas valve fault |
DOMIcondens HE 26 C | F20 | Combustion control fault |
DOMIcondens HE 26 C | A21 | Poor combustion fail |
DOMIcondens HE 26 C | A23 | Set nominal system water pressure not reached within 4 minutes |
DOMIcondens HE 26 C | A24 | 4 fillings within 24 hours |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | A34 | Supply voltage under 170V / 180V |
DOMIcondens HE 26 C | A35 | Faulty mains frequency |
OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | A35 | Mains frequency anomaly |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | A37 | Incorrect system water pressure |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | A39 | External probe fault/td> |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | A41 | Sensor positioning |
DOMIcondens HE 26 C / OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | F42 | Heating sensor fault |
DOMIcondens HE 26 C | A43 | Exchange protection activation |
DOMIcondens HE 26 C | A50 | Gas valve fault |
DOMIcondens HE 26 C | A51 | Poor combustion fault |
OPTIMAX HE PLUS 31C boiler / OPTIMAX HE PLUS 38C | A62 | No communication between electronic controller and gas valve |