Like with all appliances, your Alpha boiler can develop problems at any time and usually when you least expect it. When your Alpha boiler needs attention, it usually shows a fault code on the display panel to indicate that something is wrong and your boiler has detected an issue. Fault codes often require the expertise of a Gas Safe registered engineer, but you can sometimes clear the code and fix simple issues yourself.
If a fault code has appeared on your Alpha boiler and you can’t locate your manual, you can find the fault description and possible causes in the tables below.
Alpha E-Tec, E-Tec Plus and Evoke Combi Boiler Fault Codes
| ERROR CODE | FAULT | FAULT DESCRIPTION | POSSIBLE CAUSES |
|---|---|---|---|
| 01 | Ignition failure | Flame not detected during ignition sequence | Gas supply, ignition/sensing electrode, ignition generator or load, gas valve operation, PCB and wire connections, flue restriction or blockage |
| 02 | Overheat boiler lock out | Overheat sensor has activated | Pump or restricted flow problem, blocked heat exchanger, air in heat exchanger |
| 03 | High flue temperature | Flue sensor intervention (flue temperature too high) | Blocked or restricted primary flow, heat exchanger air flow blocked, flue restriction, flue sensor fault, air in primary heat exchanger |
| 04 | Gas valve electrical connection fault | Gas valve wiring circuit fault detected | Gas valve lead connection fault, faulty gas valve, faulty PCB |
| 05 | CH flow sensor fault | Incorrect flow sensor resistance valve | Flow sensor wire connections or sensor faulty |
| 06 | DHW sensor fault | DHW sensor resistance valve is incorrect | DHW sensor wiring connection or sensor faulty |
| 08 | Max. number of resets | Maximum number or resets reached (5) | Refer to fault history codes (INFO menu d9) to reset by turning the boiler off and on. If it will not clear, replace PCB |
| 10 | Primary system pressure low | Primary pressure switch has operated | Check expansion vessel pressure (1 bar), leak in system, expansion relief valve operated, primary pressure switch |
| 12 | DHW inlet sensor fault | Optional DHW inlet sensor resistance out of range | Check senor wiring and connections, check sensor resistance |
| 15 | Incorrect configuration | Incorrect hydraulic configuration – there is an inconsistency between the settings and signals received from the PCB | Check the settings of the ‘A’ family parameters |
| 16 | Fan fault | Fan wiring fault or fan faulty | Check fan wiring connection, fan fault, PCB fault |
| 20 | Flame sensing fault | False flame detection – flame detected but gas valve is not open | Check flame sensing electrode and lead, electrical short circuit on sensing wires, PCB fault |
| 22 | PCB fault | PCB software error | Replace PCB |
| 23 | Return sensor fault | Return sensor resistance out of range | Check sensor wiring and connections, check sensor resistance |
| 24 | Control panel button fault | Control panel button stuck in the on position | Check for jammed control panel buttons and jammed PCB buttons |
| 25 | PCB fault | PCB fault – software error | Replace PCB |
| 27 | Primary circuit overheat | Insufficient circulation in primary circuit causing overheating | Air in heat exchanger, isolation/system valves closed, check wiring/power to pump, pump seized/blocked, pump failed |
| 29 | Fan sensor fault | Flue sensor resistance out of range | Check senor wiring and connections, check sensor resistance |
| 31 | Loss of communication with external control (Alpha Climatic) | Loss of connection between the boiler and Alpha Climatic control unit | Remote control or receiver connection wiring, distance of interference of RF signal, remote control or receiver fault (check batteries if using RF controller) |
| 37 | Low supply voltage | Insufficient supply voltage to operate boiler | Check mains power supply, check for bad cable connections etc. |
| 38 | Loss of flame rectification | Flame detected but signal lost. Ignition retries after fan purge | Check flame sensing electrode and lead, check for flue gas recirculation, check the gas valve, check flue system and termination, check gas supply/working pressure, check/adjust combustion settings, check burner earth connection |
| 43 | Loss of flame rectification | Repeated loss of flame signal during operation. This fault can occur if the flue is exposed to high wind conditions (shown as E38 in the fault code history in the INFO menu) | Check as above for error code 38 |
| 47 | Reduced burner output | Flue thermostat has sensed high flue gas temperature (110°C) and reduced the burner output to prevent damage. If the temperature continues to rise the boiler will lock out and E03 will be displayed | Air in heat exchanger, restricted primary flow, heat exchanger air flow blocked, flue restriction, flue sensor fault, pump fault |
| 51 | Climatic RF communication fault | Error between communication of the Climatic transmitter and boiler receiver | Batteries require replacing |
| 60 | Pump fault | The pump is stuck or there is an electrical pump fault | Check the pump operation, it may be necessary to free the pump shaft, check the pump wiring, replace the pump |
| 61 | Air in the pump | Restricted CH flow due to air or a circuit restriction | Check flow and return valves are open, check for correct system pressure, check the system is purged properly |
| 70 | Return/flow sensor error (return reading higher than flow) | Possible wiring fault, sensors incorrectly fitted, system blocked | Check sensor wiring and connections, check sensor resistance, check circulation |
| 75 | Return/flow sensor fault | Possible failure of one or both sensors | Check sensor wiring and connections, check sensor resistance |
| 76 | Return/flow sensor fault | Possible failure of one or both sensors | Check sensor wiring and connections, check sensor resistance |
| Sr | Service reminder | Service reminder count down (0 – 36 months) has reached zero | Boiler needs servicing |
| Blank screen | Boiler fuse blown | Fuse on main PCB blown | Incorrect power supply, seized or sticking pump – check pump for free rotation, boiler component drawing excessive current, check individual components in turn |
Alpha E-Tec Regular Boiler Fault Codes
| ERROR CODE | FAULT | FAULT DESCRIPTION | POSSIBLE CAUSES |
|---|---|---|---|
| 01 | Ignition failure | Flame not detected during ignition sequence | Gas supply, check pressure tube, ignition and flame sensor electrode gaps, ignition generator or lead, gas valve setting, gas valve, PCB |
| 02 | Overheat boiler lock out | Overheat safety thermostat or flue thermal fuse (113°) has operated. If the thermal fuse has operated, the cause of its intervention must be repaired and then it must be replaced | Pump or flow problem, blocked heat exchanger, air in heat exchanger, overheat thermostat, thermal fuse |
| 03 | High flue thermostat temperature | Flue thermostat intervention (flue temperature over 108°C) | Air in heat exchanger, blocked or restricted primary flow, heat exchanger air flow blocked, flue restriction, flue sensor fault, pump fault |
| 04 | Gas valve electrical connection fault | Gas valve wiring circuit fault detected | Gas valve lead connection fault, faulty gas valve, faulty PCB |
| 05 | Heating flow sensor fault | Incorrect flow sensor resistance valve | Flow sensor wire connections or sensor faulty |
| 06 | Internal wiring error | Incorrect wiring configuration detected | Check internal wiring connections to PCB resistor R14 on plug X14 – refer to wiring diagram |
| 07 | Chimney sweep function active | Chimney sweep function is active. E07 is displayed on the Climatic remote control only | Engineers function activated by pressing the reset button for 8 seconds |
| 08 | Max. number of resets | Maximum number or resets reached (5) | Refer to fault history codes (INFO menu d9) |
| 12 | Cylinder sensor fault | Incorrect cylinder sensor resistance | Cylinder senor wiring connections, cylinder sensor faulty |
| 16 | Fan fault | Fan wiring fault or fan faulty | Check fan wiring connection, fan fault, PCB fault |
| 20 | Flame sensing fault | False flame detection – flame detected but gas valve is not open | Check flame sensing electrode and lead, PCB fault |
| 23 | Heating return sensor fault | Incorrect return sensor resistance value | Return sensor wire connections, return sensor faulty |
| 24 | Control panel button fault | Control panel button stuck in the on position | Check for jammed control panel buttons and jammed PCB buttons |
| 27 | Insufficient primary flow | Rapid temperature rise of primary sensor | Blocked or restricted primary flow, air in heat exchanger, boiler or heating circuit valve closed, pump fault, primary flow sensor fault |
| 29 | Flue sensor fault | Flue sensor resistance out of range | Check senor wiring connection, flue sensor faulty |
| 31 | Loss of communication with external control (Alpha Climatic) | Loss of connection between the boiler and Alpha Climatic control unit | Remote control or receiver connection wiring fault, remote control or receiver fault |
| 37 | Low supply voltage | Insufficient supply voltage to operate boiler | Check mains power supply, poor connection or power supply interrupted |
| 38 | Loss of flame rectification | Flame detected but signal is lost. Ignition reattempts after fan purge | Check gas supply/working pressure, check flame sensing electrode and lead, check spark generator and lead, check for flue gas recirculation, check/adjust the gas valve settings, check/adjust the fan speed settings |
| 43 | Loss of flame rectification | Repeated loss of flame signal during operation (shown as E38 in the fault code history in the INFO menu) | Check as above for error code 38 |
| 44 | Safety lock out | The boiler has attempted to fire repeatedly for the maximum time limit | Check external control (room thermostat) requests, check DHW request signal (if applicable) |
| 46 | Optional thermostat intervention | No continuity of optional thermostat circuit | Check optional thermostat and cable are not damaged or wet, check continuity of optional thermostat and circuit, check connection at X19 on PCB |
| 47 | Reduced burner output | Flue thermostat has sensed high flue gas temperature (105°C) and reduced the burner output to prevent damage. If the temperature continues to rise the boiler will lock out and E03 will be displayed | Air in heat exchanger, restricted primary flow, heat exchanger air flow blocked, flue restriction, flue sensor fault, pump fault |
| 49 | Return sensor high temperature intervention | Return sensor has detected a high temperature (90°C) on the heat exchanger return circuit | Blocked or restricted primary flow, check the diverter valve operates properly (if applicable) |
| 51 | Climatic RF communication fault | Error between communication of the Climatic transmitter and boiler receiver | Batteries require replacing, distance between boiler and Climatic control too great, interference, object blocking signal (metallic) |
| 70 | Return/flow sensor error (return reading higher than flow) | Possible wiring fault, sensors incorrectly fitted, system blocked | Check sensor wiring and connections, check sensor resistance, check circulation |
| 71 | No primary temperature increase detected | From ignition the boiler detects no temperature rise in the primary circuit | Check system filling and venting, check for air locks preventing flow, check for blocked flow or closed valves |
Alpha E-Tec S System Boiler Fault Codes
| ERROR CODE | FAULT | FAULT DESCRIPTION | POSSIBLE CAUSES |
|---|---|---|---|
| 01 | Ignition failure | Flame not detected during ignition sequence | Gas supply, ignition/sensing electrode, ignition generator or load, gas valve operation, PCB and wire connections, flue restriction or blockage |
| 02 | Overheat boiler lock out | Overheat sensor has activated | Pump or restricted flow problem, blocked heat exchanger, air in heat exchanger |
| 03 | High flue temperature | Flue sensor intervention (flue temperature too high) | Blocked or restricted primary flow, heat exchanger air flow blocked, flue restriction, flue sensor fault, air in primary heat exchanger |
| 04 | Gas valve electrical connection fault | Gas valve wiring circuit fault detected | Gas valve lead connection fault, faulty gas valve, faulty PCB |
| 05 | CH flow sensor fault | Incorrect flow sensor resistance valve | Flow sensor wire connections or sensor faulty |
| 06 | DHW setting fault | Boiler configuration error | Check parameter A6 set to 1 |
| 08 | Max. number of resets | Maximum number or resets reached (5) | Refer to fault history codes (INFO menu d9) |
| 10 | Primary system pressure low | Primary pressure switch has operated | Check expansion vessel pressure (1 bar), leak in system, expansion relief valve operated, primary pressure switch |
| 12 | Cylinder sensor fault | Incorrect cylinder sensor resistance valve | Check cylinder wiring connections, faulty sensor |
| 15 | Incorrect configuration | Incorrect hydraulic configuration – there is an inconsistency between the settings and signals received from the PCB | Check the settings of the ‘A’ family parameters |
| 16 | Fan fault | Fan wiring fault or fan faulty | Check fan wiring connection, fan fault, PCB fault |
| 20 | Flame sensing fault | False flame detection – flame detected but gas valve is not open | Check flame sensing electrode and lead, electrical short circuit on sensing wires, PCB fault |
| 23 | Return sensor fault | Return sensor resistance out of range | Check sensor wiring and connections, check sensor resistance |
| 24 | Control panel button fault | Control panel button stuck in the on position | Check for jammed control panel buttons and jammed PCB buttons |
| 25 | PCB fault | Software failure | Replace PCB |
| 29 | Flue sensor fault | Flue sensor resistance out of range | Check senor wiring and connections, check sensor resistance |
| 31 | Loss of communication with external control (Alpha Climatic) | Loss of connection between the boiler and Alpha Climatic control unit | Remote control or receiver connection wiring, distance of interference of RF signal, remote control or receiver fault (check batteries if using RF controller) |
| 37 | Low supply voltage | Insufficient supply voltage to operate boiler | Check mains power supply, check for bad cable connections etc. |
| 38 | Loss of flame rectification | Flame detected but signal lost. Ignition retries after fan purge | Check flame sensing electrode and lead, check for flue gas recirculation, check the gas valve, check flue system and termination, check gas supply/working pressure, check/adjust combustion settings, check burner earth connection |
| 43 | Loss of flame rectification | Repeated loss of flame signal during operation. This fault can occur if the flue is exposed to high wind conditions (shown as E38 in the fault code history in the INFO menu) | Check as above for error code 38 |
| 47 | Reduced burner output | Flue thermostat has sensed high flue gas temperature (110°C) and reduced the burner output to prevent damage. If the temperature continues to rise the boiler will lock out and E03 will be displayed | Air in heat exchanger, restricted primary flow, heat exchanger air flow blocked, flue restriction, flue sensor fault, pump fault |
| 51 | Climatic RF communication fault | Error between communication of the Climatic transmitter and boiler receiver | Batteries require replacing |
| 60 | Pump fault | The pump is stuck or there is an electrical pump fault | Check the pump operation, it may be necessary to free the pump shaft, check the pump wiring, replace the pump |
| 61 | Air in the pump | Restricted CH flow due to air or a circuit restriction | Check flow and return valves are open, check for correct system pressure, check the system is purged properly |
| 75 | Return/flow sensor fault | Possible failure of one or both sensors | Check sensor wiring and connections, check sensor resistance |
| 76 | Return/flow sensor fault | Possible failure of one or both sensors | Check sensor wiring and connections, check sensor resistance |
Alpha ProTec Plus System Boiler Fault Codes
| ERROR CODE | FAULT DESCRIPTION | POSSIBLE CAUSES |
|---|---|---|
| 0A1 | Ignition failure | Check for correct gas supply (purged and valves open), check ignition electrode position and spark, check flame sensing electrode connections, check gas valve operation |
| 0A2 | Flame detection fault | Check flame sensing electrode connections, check for a short circuit to the electrode or wires |
| 0A3 | Overheat thermostat lock-out | Check for water circulation, check for air in the heat exchanger, check for system restrictions and blockages, check overheat thermostat and connections, reset overheat thermostat if required |
| 0A4 | Air pressure switch fault | Check flue for blockage/restrictions, check air pressure switch/connections, check fan functions |
| 0A5 | Fan speed fault | Check flue and ventilation, check air inlet manifold and pipe, check for fan damage/fault, check fan wire connection. |
| 0A7 | High flue temperature fault | Check for air in the primary heat exchanger, check for system restriction causing overheating, check the flue run for restrictions or blockages |
| 0A8 | Flame circuit fault | Check for correct gas supply (purged and valves open), check ignition electrode position and spark, check flame sensing electrode gap and connections |
| 0A9 | Gas valve electrical error | Check gas valve plug and wiring, check main PCB, check gas valve operation, check for gas contamination |
| 0A15 | Flow and return sensor anomaly detected. The senor shows an incorrect temperature valve | Check for poor or incorrect circulation, check for external circuit influences, check resistances of flow and return sensors |
| 0A18 | Flow and return sensor anomaly detected. Sudden temperature change detected on the flow or return sensor | Check system circulation, check operation of zone valves, check resistances and function of flow and return sensors |
| 0A21 | Main PCB fault | Check all electrical connections, check for water ingress in connections |
| 0A30 | Flow sensor short circuit | Check flow sensor connections and wires, check for water ingress in connections |
| 0A31 | Flow sensor out of range. Sensor measures a temperature outside normal working range | Check flow sensor connections and damaged wires, check sensor resistance valves |
| 0A37 | Pro Tec 50 – Insufficient system flow. If the system flow is too low for a certain period, the boiler will switch off Pro Tec 70, 90, 115 – Insufficient system pressure. If the system pressure is too low, the boiler switches off | Check the flow switch reading P05, check the system for restriction or shut valves, check pump function, check system pressure Check the system pressure is 1 – 2 bar. If necessary refill to the correct pressure |
| 0A43 | Return sensor short circuit | Check return sensor connections and wires, check for water ingress in connections |
| 0A44 | Return sensor out of range. Sensor measures a temperature outside normal working range | Check return sensor connections and damaged wires, check return sensor resistance valves |
| 0A80 | Flow and return sensor connection fault. Fault may occur after several minutes of boiler operation | Check the wires are connected to the correct sensors |
| 0E2 | Flame sensing fault | Check flame sensing electrode connections, check for a short circuit to the electrode or wire |
| 0E13 | Maximum number of resets reached. More than five reset attempts have been reached within 15 minutes | Investigate initial fault code displayed. Switch the power supply Off/On to clear this code |
| 0E25 | Main PCB fault | Check all electrical connections, check for water ingress in connections |
| 0E32 | DHW sensor short circuit | Check DHW sensor connections and wires, check for water ingress in connections |
| 0E33 | DHW sensor out of range. DHW sensor measures a temperature outside normal working range | Check DHW sensor connections and damaged cables, check DHW sensor resistance valves |
| 0E34 | Low power supply voltage | Check electrical socket connections, check external power supply, check for possible power disruptions |
| 0E37 | Insufficient system pressure (Pro Tec Plus 70, 90, 115) or pressure and flow (Pro Tec Plus 50) | Check the system for circulation and restrictions, check system pressure and gauge, check pressure switch and connections |
| 0E45 | Flue sensor short circuit | Check flue sensor connections and wires, check for water ingress in connections |
| 0E46 | Flue sensor out of range. Flue sensor measures a temperature outside normal working range | Check flue sensor connections and wires, check flue sensor resistance valves |
| 0E81 | Flow and return sensor anomaly detected. The sensor shows an incorrect temperature valve | Check for poor or incorrect circulation, check for external circuit influences, check resistances of flow and return sensors |
| 0E98 | Simple cascade communication error | Check ‘M to O’ connections, check compatible software on PCB |
| 0E99 | Simple cascade communication error | Check wiring connections on all boilers, check correct configurations, parameter 38 |
| FE94 | Display PCB fault | Check electrical connections to display board, check for water ingress in connections, check for damage to button or LCD screen |
| FE95 | External flow sensor out of range or short circuit. External flow sensor measures a temperature outside normal working range | Check external flow sensor connections and damaged wires, check external flow sensor resistance valves between 5 and 0 |
| FE96 | External sensor fault | Check external sensor connections and wires, check for water ingress in connections, check boiler parameter settings are correct |
| FE97 | Boiler PCB configuration error. This may occur if the main PCB or display PCB is changed | Check all electrical connections, check for correct parameter settings on PCB heck for correct parameter settings on PCB. Press ‘-‘ CH button until ‘AUTO’ appears, then press and hold ‘RESET’ button until ‘bu1’ appears |
| Red pump LED | Pump fault | Three possible causes include low power supply voltage, seized rotor or an electrical, pump, wiring or PCB fault |
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