Alpha Fault Codes

Welcome to the fault-codes section of this site. The following table or page contains the information required to help repair and diagnose the fault codes being shown on the boiler display. You may be guided through the fault finding sequence or steps, for rectifying your boiler with this fault code. Suggested repair solutions may be provided by a link to a repair page. NB Some fault codes are only applicable to a specific range of boilers only.

Faultcode FaultPossible CauseModel Specific
1LinkIgnition failureGas supply, pressure tubes, ignition electrode, flame sensor electrode, ignition generator, lead flame sensor, electrode lead, gas valve setting, gas valve printed circuit board (PCB)Alpha Boiler
2LinkOverheat boiler lock outPump or flow problem, blocked heat exchanger, air in heat exchanger, overheat thermostat, thermal fuse (if open circuit then replace primary heat exchanger)Alpha Boiler
3LinkHigh flue thermostat temperatureBlocked or restricted primary flow, heat exchanger air flow blocked, flue restriction, flue sensor faultAlpha Boiler
4LinkGas valve electrical connection faultGas valve lead connection fault, faulty gas valve or faulty printed circuit board (PCB)Alpha Boiler
5LinkHeating flow sensor faultFlow sensor wire connections, flow sensor faultyAlpha Boiler
6LinkDomestic how water (DHW) sensor faultDHW sensor wiring connection or DHW sensor faultyAlpha Boiler
8LinkMaximum number of resetsRefer to fault history codesAlpha Boiler
10LinkPrimary system pressure lowCheck expansion vessel pressure (1 bar), leak in system, expansion relief valve operated or primary pressure switchAlpha Boiler
12LinkCylinder sensor fault (FlowSmart only)Cylinder sensor wiring connections or cylinder sensor faultyAlpha Boiler
15LinkInternal wiring errorCheck internal wiring connections to printed circuit board (PCB), Combi boiler domestic hot water (DHW) sensor X4, System boiler link X14Alpha Boiler
16LinkFan faultFan wiring connections, fan fault or printed circuit board (PCB) faultAlpha Boiler
20LinkFlame sensing faultCheck flame sensing electrode and lead printed circuit board (PCB) faultAlpha Boiler
24LinkControl panel button faultJammed control panel or printed circuit board (PCB) buttonsAlpha Boiler
25LinkOverheat lock outAir 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 closedAlpha Boiler
27LinkInsufficient primary flowBlocked or restricted primary flow, air in heat exchanger, boiler or heating circuit valve closed, pump fault or primary flow sensor faultAlpha Boiler
29LinkFlue sensor faultSensor wiring connection or flue sensor faultyAlpha Boiler
31LinkLoss of communication with external control (Alpha Climatic)Remote control or receiver connection wiringAlpha Boiler
37LinkLow supply voltageCheck mains power supplyAlpha Boiler
38LinkLoss of flame rectificationFlame sensing electrode and lead, check flue gas recirculation, check the gas valve settings and check the fan speed settingsAlpha Boiler
43LinkLoss of flame rectificationCheck gas supply working, check flame sensing electrode and lead, check for flue gas recirculation, check the gas valve settings, check the fan speed settingsAlpha Boiler
44LinkSafety lock outCheck external control (room thermostat) requests and rapid on/off hot tap requestsAlpha Boiler
46LinkExternal sensor interventionExternal sensor and cable damaged or wet, continuity of external sensor and circuit, check connection at X19 on printed circuit board (PCB) and sensor connecting blockAlpha Boiler
47LinkReduced burner outputAir in heat exchanger, restricted primary flow, heat exchanger air flow blocked, flue restriction, flue sensor fault or pump faultAlpha Boiler
51LinkClimatic RF communication faultBatteries need replacing, distance between boiler and climatic control too great, interference object blocking signal (metallic)Alpha Boiler
60LinkPump error (stuck or there is an electrical pump fault)Pump operation (may need to free the pump shaft), issue with pump wiring or pump replacement needed.E-Tec, E-Tec Plus, Evoke Combi
61LinkAir in the pump (restricted central heating flow)Flow and Return valves may not be open, iIncorrect system pressure, system not purged properly or flow return valves are open.E-Tec, E-Tec Plus, Evoke Combi
70LinkReturn/flow sensor, Exchange from possible wiring faultIssues with sensor resistance.E-Tec, E-Tec Plus, Evoke Combi
75 / 76LinkReturn/flow sensor fault from possible failure of one or both sensorsIssues with sensor resistance.E-Tec, E-Tec Plus, Evoke Combi
SRLinkService reminderService reminder countdown has reached 0 (this will not stop boiler from working) _ boiler needs servicing.E-Tec, E-Tec Plus, Evoke Combi
0A1 LinkIgnition failure Issue with gas supply.
Ignition electrode position and spark issues.
Protec Plus
0A2 LinkFlame detection faultFlame sensing electrode connections.
A short circuit to the electrode or wires.
Protec Plus
0A3 LinkOverheat thermostat lock-outFlame sensing electrode connections.
A short circuit to the electrode or wires.
Protec Plus
0A5 LinkFan speed faultProblem with flue /ventilation.
Issue with air inlet manifold and pipe.
Damage or fault with fan.
Fan wire connections
Protec Plus
0A7 LinkHigh flue temperature faultAir in the primary heat exchanger.
System restrictions causing overheating.
Flue run may have restrictions or blockages.
Protec Plus
0A8 LinkFlame circuit faultIncorrect gas supply.
Ignition electrode position and spark.
Issues with flame sensing electrode gap and connections.
Protec Plus
0A9 LinkGas valve electrical errorValve connection issues.
Main PCB.
Gas valve operation issues.
Gas contamination.
Protec Plus
0A15 LinkFlow and return sensor anomaly detected.
(incorrect temperature value shown on sensor.)
Poor or incorrect circulation.
External circuit influences.
Problem with resistances of flow and return sensors
Protec Plus
0A16 LinkFlow sensor temperature rise incorrect (time taken for flow temperature to rise is too long.System circulation issues.
System volume or flow is too high.
Boiler output is insufficient for the system.
Protec Plus
0A17 LinkReturn sensor temperature rise incorrect (time taken for flow temperature to rise is too long.System circulation issues.
System volume or flow is too high.
Boiler output is insufficient for the system.
Protec Plus
0A18 LinkFlow and return sensor anomaly detected. Sudden temperature change detected on the flow or return sensor.System circulation issues.
Problem with operation of zone valves.
Resistances and function of flow and return sensors needs checking.
Protec Plus
0A21 LinkMain PCB faultElectrical connections.
Water ingress in connections.
Protec Plus
0A30 LinkFlow sensor short circuitFlow sensor connections and wires need checking.
Water ingress in connections.
Protec Plus
0A31 LinkFlow sensor out of range. (sensor measures a temperature not in normal range.)Problem with flow sensor connections and damaged wires.
Sensor resistance values wrong.
Protec Plus
0A37 Ð Pro Tec 50 LinkInsufficient system flow (if the system flow is too low for a certain length of time boiler will switch off)Flow switch reading needs checking.
Restrictions or shut valves in system.
Pump function issues.
System pressure issues.
Protec Plus
0A37 Ð Pro tec 70, 90, 115 LinkInsufficient system pressure (if the system pressure is too low the boiler switches off.)System pressure needs to be 1 – 2 bar if its not the pressure needs refilling to the correct amountProtec Plus
0A43 LinkReturn sensor short circuitProblem with return sensor connections and wires.
Water ingress in connections
Protec Plus
0A44 LinkReturn sensor out of range.
Sensor measures a temperature outside normal working range
Return sensor connections and damaged wires.
Return sensor resistance values need checking.
Protec Plus
0A80 LinkFlow and return sensor connection fault (may occur after several minutes of boiler operation.)Wires are not connected to the correct sensors.Protec Plus
0E2LinkFlame sensing fault.Flame sensing electrode connections need checking.
Short circuit to the electrode or wire.
Protec Plus
0E13 LinkMaximum number of resets reached. (Over 5 reset attempts have been reached within 15 minutes.)Investigate initial fault code displayed.
Power supply needs to be turned Off/On to clear this code
Protec Plus
0E25 LinkMain PCB faultAll electrical connections need to be checked.
Water ingress in connections.
Protec Plus
0E34 LinkDHW sensor out of range (measures a temperature outside normal working range.)DHW sensor connections and damaged cables.
Issues with DHW sensor resistance values
Protec Plus
0E33 LinkLow power supply voltageElectrical socket connection issues.
Problem with external power supply.
Possible power disruptions
Protec Plus
0E37 LinkInsufficient system pressureSystem needs checking for circulation and restrictions.
System pressure and gauge needs checking.
Pressure switch and connections need checking.
Protec Plus
0E45 LinkFlue sensor short circuitFlue sensor connections and wires need checking.
Water ingress in connections
Protec Plus
0E46 LinkFlue sensor out of range (measures a temperature outside of normal working range)Flue sensor connections, wires and flue sensor resistance values need checking.Protec Plus
0E81 LinkFlow and return sensor anomaly detected (the sensor shows an incorrect temperature value)Poor or incorrect circulation / external circuit influences resistance of flow return sensors need checkingProtec Plus
0E98 LinkFlow and return sensor anomaly detected (sensor shows incorrect temperature value)M to O Connections need checking
Compatible software on PCB needs checking
Protec Plus
0E99 LinkSimple cascade communication errorWiring connections needs checking on all boilers.
Configuration, parameter 38.
Protec Plus
FE94 LinkDisplay PCB fault.Electrical connections to display board need checking.
Water ingress in connections.
Damage to buttons or LCD screen.
Protec Plus
FE95 LinkExternal flow sensor out of range or short circuit/
External flow sensor measures a temperature outside of normal working
range.
External flow sensor connections and wires need checking for damage. External flow sensor resistance values need checking to make sure they are between 5 and 0Protec Plus
FE96 LinkExternal sensor faultExternal sensor connections and wires need checking.
Water ingress in connections.
Boiler parameter settings are incorrect
Protec Plus
FE97 LinkBoiler PCB configuration error (may occur if the main PCB or display PCB is changed.)All electrical connections.
Incorrect parameter settings on PCB.
Press ‘-‘ CH button until ‘AUTO’ appears, then press and
hold ‘RESET’ button until ‘bu1’ appears
Protec Plus
No lights onLinkElectricity faultCheck your electricity supplyAlpha Flashing
Illuminated red A or BLinkBurner has failed to lightRotate selector switch to the reset position (3) and the ignition sequence will restart after a delay of about 30 secondsAlpha Flashing
Illuminated yellow B or CLinkBurner is alightNo action requiredAlpha Flashing
Flashing red A or BLinkOverheat thermostat has operated / Temperature sensor faultRotate selector switch to the reset position (3) to resetAlpha Flashing
Flashing yellow every 5 seconds or illuminated green DLinkElectrical supply to the boiler is onNo Action RequiredAlpha Flashing
Flashing yellow B or flashing Red ALinkTemperature sensor faultContact a heating engineerAlpha Flashing
Illuminated red A and flashing yellow B or Flashing red A and flashing red BLinkBlocked flue or fan faultAlpha Flashing
Flashing yellow or flashing Red A or Flashing (alternating) red A and flashing (alternating) yellow BLinkSystem pressure is very low and re-pressurisation is requiredæAlpha Flashing
Illuminated red A and flashing yellow BLinkPump fault or restricted flowAlpha Flashing
Flashing red A and Flashing red B and flashing yellow CLinkTemperature sensor wiring or flow and return connections incorrectAlpha Flashing
Flashing red A and flashing red B and flashing yellow C indicatorsLinkFlue temperature too high (air in the heat exchanger, heat exchanger blockedAlpha Flashing
1LinkIgnition failureCheck the gas supply, pressure tubes, ignition electrode, flame sensor electrode, ignition generator or lead flame sensor, gas valve setting and PCB.Alpha E-Tec Regular
2LinkOverheat boiler lockoutPump or flow problem. Caused by a blocked heat exchanger, air in heat exchanger, overheated thermostat, thermal fuse (if open circuit then replace primary heat exchanger).Alpha E-Tec Regular
3LinkHigh flue thermostat temperatureBlocked or restricted primary flow. Heat exchanger air flow blocked, flue restriction, flue sensor fault.Alpha E-Tec Regular
4LinkGas valve electrical connection faultGas valve lead connection fault. Faulty gas valve or faulty PCB.Alpha E-Tec Regular
5LinkHeating flow sensor faultFlow sensor wire connections. Flow sensor faulty.Alpha E-Tec Regular
6LinkInternal wiring errorIncorrect wiring configuration detected. Internal wiring connections to PCB need checking.Alpha E-Tec Regular
7LinkChimney sweep function is activeChimney sweep function is active. E07 is displayed on the climatic remote control.Alpha E-Tec Regular
8LinkMaximum number of resetsRefer to fault history codes (INFO menud9)Alpha E-Tec Regular
12LinkCylinder sensor fault (FlowSmart only)Cylinder sensor wiring connection _ cylinder sensor faulty.Alpha E-Tec Regular
16LinkFan faultCheck fan wiring connection, fan fault or PCB fault.Alpha E-Tec Regular
20LinkFlame sensing faultCheck flame sensing electrode and lead PCB for faults.Alpha E-Tec Regular
23LinkHeating return sensor faultIncorrect return sensor resistance value _ return sensor wire connections or sensor could be faulty.Alpha E-Tec Regular
24LinkControl panel button faultControl panel button is stuck in the ïonÍ position _ check for jammed control panel buttons or jammed PCB button.æAlpha E-Tec Regular
27LinkInsufficient primary flowBlocked or restricted primary flow. Air in heat exchanger, boiler or heating circuit valve closed, pump fault or primary flow sensor fault.Alpha E-Tec Regular
29LinkFlue sensor faultCheck sensor wiring connection _ flue sensor faulty.Alpha E-Tec Regular
31LinkLoss of communication with external control (Alpha Climatic)Remote control or receiver connection wiring.Alpha E-Tec Regular
37LinkLow supply voltageCheck mains power supply.Alpha E-Tec Regular
38LinkLoss of flame rectificationCheck flame sensing electrode and lead and for flue gas recirculation. Check or adjust the gas valve settings. Check or adjust the fan speed settings.Alpha E-Tec Regular
43LinkLoss of flame rectificationCheck gas supply/working pressure, flame sensing electrode and lead, check for flue gas recirculation, check/adjust the gas valve settings, check/adjust the fan speed settings.Alpha E-Tec Regular
44LinkSafety lockoutCheck external control (room thermostat) requests. Rapid on/off hot tap requests.Alpha E-Tec Regular
45LinkHigh-temperature differenceThe boiler is detecting an unexpected increase between the system flow and return sensors. Boiler output is limited for boiler protection and once restored the boiler resumes regular operation.Alpha E-Tec Regular
46LinkOptional thermostat interventionNo continuity of optional thermostat circuit _ check the optional thermostat and cable are not damaged or wet.Alpha E-Tec Regular
47LinkReduced burner outputFlue thermostat has sensed high flue gas temperature and reduced the burner output to prevent damage. If the temperature continues to rise the boiler will lockout and the E03 error code will be displayed. This could be due to air in the heat exchanger, restricted primary flow or heat exchanger air blocked.Alpha E-Tec Regular
49LinkReturn sensor high temperature interventionReturn sensor has detected a high temperature on the exchanger return circuit.Alpha E-Tec Regular
51LinkClimatic RF communication faultThe error between the communication of the climatic transmitter and boiler receiver. Could mean the batteries need replacing or the distance between the boiler and climatic control is too great or a metal object is blocking the signal.æAlpha E-Tec Regular
70LinkReturn flow sensor erroræPossible wiring faults sensor is incorrectly fitted or the system is blocked _ check the sensor wiring and connections, also check sensor resistance and circulation.Alpha E-Tec Regular
71LinkNo primary temperature increase detectedæFrom ignition the boiler detects no temperature rise in the primary circuit _ check system filling and venting, air locks preventing flow check, blocked flow or closed valves.Alpha E-Tec Regular

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