Boiler Fault Finder

Alpha Boiler Error Codes

,

Fault Code Model Affected Fault Possible Cause
1 All Ignition failure Gas supply Check pressure tubes Ignition electrode gap Flame sensor electrode gap Ignition generator or lead Flame sensor electrode lead Gas valve setting Gas valve PCB
2 All Overheat boiler lock out Pump or flow problem Blocked heat exchanger Air in heat exchanger Overheat thermostat Thermal fuse (if open circuit then replace primary heat exchanger)
3 All High flue thermostat temperature Blocked or restricted primary flow Heat exchanger air flow blocked Flue restriction Flue sensor fault
4 All Gas valve electrical connection fault Gas valve lead connection fault Faulty gas valve Faulty PCB
5 All Heating flow sensor fault Flow sensor wire connections Flow sensor faulty
6 All DHW sensor fault DHW sensor wiring connection DHW sensor faulty
8 All Maximum number of resets Refer to fault history codes (INFO menu d9)
10 All Primary system pressure low Check expansion vessel pressure (1 bar) Leak in system Expansion relief valve operated Primary pressure switch
12 All “Cylinder sensor fault (FlowSmart only)” “Cylinder sensor wiring connections Cylinder sensor faulty”
15 All Internal wiring error Check internal wiring connections to PCB Combination boiler DHW sensor X4 System boiler link X14 Refer to wiring diagram
16 All Fan fault Check fan wiring connections Fan fault PCB fault
20 All Flame sensing fault Check flame sensing electrode and lead PCB fault
24 All Control panel button fault Check for jammed control panel buttons Check for jammed PCB buttons
25 All Overheat lock out Air in heat exchanger Blocked or restricted primary flow Heat exchanger air flow blocked Flue restriction Flue sensor fault Pump fault Boiler or Heating circuit valve closed
27 All Insufficient primary flow Blocked or restricted primary flow Air in heat exchanger Boiler or heating circuit valve closed Pump fault Primary flow sensor fault
29 All Flue sensor fault Check sensor wiring connection Flue sensor faulty
31 All Loss of communication with external Control (Alpha Climatic) Remote control or receiver connection wiring Remote control or receiver
37 All Low supply voltage Check mains power supply
38 All Loss of flame rectification Check flame sensing electrode and lead Check for flue gas recirculation Check/adjust the gas valve settings Check/adjust the fan speed settings
43 All Loss of flame rectification “Check gas supply/working pressure Check flame sensing electrode and lead Check for flue gas recirculation Check/adjust the gas valve settings Check/adjust the fan speed settings”
44 All Safety lock out Check external control (room thermostat) requests Rapid on/off hot tap requests
46 All External sensor intervention Check external sensor and cable are not damaged or wet Check continuity of external sensor and circuit Check connection at X19 on PCB and sensor connecting block
47 All Reduced burner output Air in heat exchanger Restricted primary flow Heat exchanger air flow blocked Flue restriction Flue sensor fault Pump fault
51 All Climatic RF communication fault Batteries require replacing Distance between boiler and climatic control too great Interference Object blocking signal (metallic)
No lights on Alpha C23, C27 CB, CB50, CD50, CDC, CDR, CDS, CDX, HE, HECB, HESY Electricity fault Check your electricity supply
Illuminated red A or B Alpha C23, C27 CB, CB50, CD50, CDC, CDR, CDS, CDX, HE, HECB, HESY Burner has failed to light Rotate selector switch to the reset position (3) and the ignition sequence will restart after a delay of about 30 seconds
Illuminated yellow B or C Alpha C23, C27 CB, CB50, CD50, CDC, CDR, CDS, CDX, HE, HECB, HESY Burner is alight No action required
Flashing red A or B Alpha C23, C27 CB, CB50, CD50, CDC, CDR, CDS, CDX, HE, HECB, HESY Overheat thermostat has operated / Temperature sensor fault Rotate selector switch to the reset position (3) to reset
Flashing yellow every five seconds or Illuminated Green D Alpha C23, C27 CB, CB50, CD50, CDC, CDR, CDS, CDX, HE, HECB, HESY Electrical supply to the boiler is on No Action Required
Flashing yellow B or flashing Red A Alpha C23, C27, CB, CB50, CD50, CDC, CDR, CDS, CDX, HE,HECB, HESY, Temperature sensor fault Contact a professional
Illuminated red A and flashing yellow B or Flashing red A and flashing red B Alpha C23, C27, CB, CB50, CD50, CDC, CDR, CDS, CDX, HE,HECB, HESY, Blocked flue or fan fault contact a professional
Flashing yellow or flashing Red A or Flashing (alternating) red A and flashing (alternating) yellow B Alpha C23, C27, CB, CB50, CD50, CDS, CDX, HE,HECB, HESY, System pressure is very low and re-pressurisation is required Contact a professional
Illuminated red A and flashing yellow B Alpha C27, CB, CB50, HE,HECB Pump fault or restricted flow Contact a professional
Flashing red A and Flashing red B and flashing yellow C Alpha CDR Temperature sensor wiring or flow and return connections incorrect Contact a professional
Flashing red A and flashing red B and flashing yellow C indicators Alpha CDS, CDX Flue temperature too high (air in the heat exchanger, heat exchanger blocked Contact a professional