Alpha
Alpha Boilers Error Codes
Complete list of fault codes and troubleshooting guides. Use the search below to find your specific error.
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E01
Boiler does not ignite, display shows E01 shortly after a heating or hot water demand.
Ignition Failure / Flame Not Detected
E02
Boiler locks out with E02, fan runs briefly then stops, no ignition.
Flue Gas / Air Pressure Fault
E03
Boiler shows E03 and shuts down; may occur shortly after ignition or during operation.
Overheat Thermostat Trip
E04
Boiler displays E04 and will not start; may occur after power interruption or wiring work.
Flow Temperature Sensor (NTC) Fault
E05
Boiler shows E05, runs briefly then shuts down, often associated with incorrect temperature readings.
Return Temperature Sensor (NTC) Fault
E06
Boiler displays E06 when hot water is requested; heating may still work in some cases.
DHW Temperature Sensor (Hot Water NTC) Fault
E07
Boiler shows E07 and will not fire; may occur after wiring changes or PCB replacement.
Flame Detection Circuit Fault
E08
Boiler displays E08 and locks out; fan may not start.
Fan Speed / Fan Feedback Fault
E09
Boiler shows E09 and will not ignite; may occur after gas supply interruption.
Gas Valve Control Fault
E10
Boiler displays E10 and stops; pressure gauge may read low or zero.
Low Water Pressure / System Pressure Fault
E11
Boiler shows E11; may occur during hot water use or heating, often with fluctuating temperatures.
Flow Rate / Flow Switch Fault
E12
Boiler displays E12 and locks out; may be associated with incorrect temperature readings or rapid cycling.
Primary Heat Exchanger Sensor / Calibration Fault
E13
Boiler shows E13; may occur during flue or condensate issues, often in condensing mode.
Condensate System Fault
E14
Boiler displays E14 and will not operate; often after a power surge or wiring fault.
Main PCB / Control Board Fault
E15
Boiler shows E15; may be accompanied by unusual noises from the pump area.
Pump Circulation Fault
E16
Boiler displays E16; may occur when external controls are calling for heat.
External Control / Thermostat Fault
E17
Boiler shows E17 and locks out; may be associated with very high or very low mains voltage.
Mains Supply / Voltage Fault
E18
Boiler displays E18; may occur when the flue system has been altered or extended.
Flue Configuration / Sensor Fault
E19
Boiler shows E19; may occur intermittently, often during hot water draw-off.
Plate Heat Exchanger Temperature Differential Fault
E20
Boiler displays E20 and will not operate; may occur after service mode or parameter changes.
Configuration / Parameter Error
Symptom
Boiler display is blank and the unit appears completely dead.
No Power / Dead Boiler
Symptom
Boiler display is on but unresponsive; buttons do not work or menu is frozen.
User Interface / Control Panel Fault
Symptom
Boiler does not fire for central heating but provides hot water normally.
Heating Demand / Diverter Valve Fault
Symptom
Boiler does not fire for hot water but central heating works normally.
DHW Demand / Diverter Valve Fault
Symptom
Boiler does not respond to room thermostat; heating stays off even when thermostat is calling for heat.
Control Signal Failure
Symptom
Boiler emits a burning smell or plastic smell during operation.
Overheating Electrical Component or Dust Burn-off
Symptom
Boiler flue terminal shows signs of staining or water dripping from joints.
Flue Condensation / Leakage
Symptom
Boiler frequently loses pressure and needs regular topping up.
Chronic Pressure Loss
Symptom
Boiler ignites but shuts down after a few seconds without showing a specific error code.
Flame Instability / Short Cycling
Symptom
Boiler is very noisy during operation, with whirring, grinding, or high-pitched sounds.
Mechanical Noise from Fan or Pump
Symptom
Boiler leaking water from underneath the casing or from pipe connections.
Internal Water Leak
Symptom
Boiler makes loud banging or knocking noises (kettling) during operation.
Kettling Due to Scale or Sludge
Symptom
Boiler runs but hot water temperature fluctuates or runs hot then cold at the taps.
Unstable Domestic Hot Water Temperature
Symptom
Boiler runs but radiators do not get hot or only partially heat up.
Poor Heating Circulation
Symptom
Boiler starts and stops frequently (short cycling) even when there is a continuous demand for heat.
Short Cycling Due to Oversizing or Control Issues
Symptom
Boiler's pressure gauge rises rapidly when heating is on and may discharge water from the safety pipe.
Expansion Vessel / Pressure Relief Valve Issue
Symptom
Radiators get hot when only hot water is being used (no heating demand set).
Diverter Valve Passing / Stuck Mid-Position
| Error Code | Symptom | Fault Type | Guide |
|---|---|---|---|
| E01 |
Boiler does not ignite, display shows E01 shortly after a heating or hot water demand.
|
Ignition Failure / Flame Not Detected | View Details |
| E02 |
Boiler locks out with E02, fan runs briefly then stops, no ignition.
|
Flue Gas / Air Pressure Fault | View Details |
| E03 |
Boiler shows E03 and shuts down; may occur shortly after ignition or during operation.
|
Overheat Thermostat Trip | View Details |
| E04 |
Boiler displays E04 and will not start; may occur after power interruption or wiring work.
|
Flow Temperature Sensor (NTC) Fault | View Details |
| E05 |
Boiler shows E05, runs briefly then shuts down, often associated with incorrect temperature readings.
|
Return Temperature Sensor (NTC) Fault | View Details |
| E06 |
Boiler displays E06 when hot water is requested; heating may still work in some cases.
|
DHW Temperature Sensor (Hot Water NTC) Fault | View Details |
| E07 |
Boiler shows E07 and will not fire; may occur after wiring changes or PCB replacement.
|
Flame Detection Circuit Fault | View Details |
| E08 |
Boiler displays E08 and locks out; fan may not start.
|
Fan Speed / Fan Feedback Fault | View Details |
| E09 |
Boiler shows E09 and will not ignite; may occur after gas supply interruption.
|
Gas Valve Control Fault | View Details |
| E10 |
Boiler displays E10 and stops; pressure gauge may read low or zero.
|
Low Water Pressure / System Pressure Fault | View Details |
| E11 |
Boiler shows E11; may occur during hot water use or heating, often with fluctuating temperatures.
|
Flow Rate / Flow Switch Fault | View Details |
| E12 |
Boiler displays E12 and locks out; may be associated with incorrect temperature readings or rapid cycling.
|
Primary Heat Exchanger Sensor / Calibration Fault | View Details |
| E13 |
Boiler shows E13; may occur during flue or condensate issues, often in condensing mode.
|
Condensate System Fault | View Details |
| E14 |
Boiler displays E14 and will not operate; often after a power surge or wiring fault.
|
Main PCB / Control Board Fault | View Details |
| E15 |
Boiler shows E15; may be accompanied by unusual noises from the pump area.
|
Pump Circulation Fault | View Details |
| E16 |
Boiler displays E16; may occur when external controls are calling for heat.
|
External Control / Thermostat Fault | View Details |
| E17 |
Boiler shows E17 and locks out; may be associated with very high or very low mains voltage.
|
Mains Supply / Voltage Fault | View Details |
| E18 |
Boiler displays E18; may occur when the flue system has been altered or extended.
|
Flue Configuration / Sensor Fault | View Details |
| E19 |
Boiler shows E19; may occur intermittently, often during hot water draw-off.
|
Plate Heat Exchanger Temperature Differential Fault | View Details |
| E20 |
Boiler displays E20 and will not operate; may occur after service mode or parameter changes.
|
Configuration / Parameter Error | View Details |
| – |
Boiler display is blank and the unit appears completely dead.
|
No Power / Dead Boiler | View Details |
| – |
Boiler display is on but unresponsive; buttons do not work or menu is frozen.
|
User Interface / Control Panel Fault | View Details |
| – |
Boiler does not fire for central heating but provides hot water normally.
|
Heating Demand / Diverter Valve Fault | View Details |
| – |
Boiler does not fire for hot water but central heating works normally.
|
DHW Demand / Diverter Valve Fault | View Details |
| – |
Boiler does not respond to room thermostat; heating stays off even when thermostat is calling for heat.
|
Control Signal Failure | View Details |
| – |
Boiler emits a burning smell or plastic smell during operation.
|
Overheating Electrical Component or Dust Burn-off | View Details |
| – |
Boiler flue terminal shows signs of staining or water dripping from joints.
|
Flue Condensation / Leakage | View Details |
| – |
Boiler frequently loses pressure and needs regular topping up.
|
Chronic Pressure Loss | View Details |
| – |
Boiler ignites but shuts down after a few seconds without showing a specific error code.
|
Flame Instability / Short Cycling | View Details |
| – |
Boiler is very noisy during operation, with whirring, grinding, or high-pitched sounds.
|
Mechanical Noise from Fan or Pump | View Details |
| – |
Boiler leaking water from underneath the casing or from pipe connections.
|
Internal Water Leak | View Details |
| – |
Boiler makes loud banging or knocking noises (kettling) during operation.
|
Kettling Due to Scale or Sludge | View Details |
| – |
Boiler runs but hot water temperature fluctuates or runs hot then cold at the taps.
|
Unstable Domestic Hot Water Temperature | View Details |
| – |
Boiler runs but radiators do not get hot or only partially heat up.
|
Poor Heating Circulation | View Details |
| – |
Boiler starts and stops frequently (short cycling) even when there is a continuous demand for heat.
|
Short Cycling Due to Oversizing or Control Issues | View Details |
| – |
Boiler's pressure gauge rises rapidly when heating is on and may discharge water from the safety pipe.
|
Expansion Vessel / Pressure Relief Valve Issue | View Details |
| – |
Radiators get hot when only hot water is being used (no heating demand set).
|
Diverter Valve Passing / Stuck Mid-Position | View Details |
No matching codes found
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