Alpha
E-Tec Plus 20S
System Boiler
20kW
2015-present
ErP A
82 fault codes
<p>The E-Tec Plus 20S is a system boiler from Alpha, available at 20kW output. Produced 2015-present.</p>
E-Tec Plus 20S Fault Codes 82
Code
Description
Severity
Type
0A1
Ignition Failure (ProTec Plus)
On Alpha ProTec Plus commercial boilers, 0A1 indicates ignition failure — gas supply or valve issue.
Medium
Engineer
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0A5
Fan Speed Fault (ProTec Plus)
On Alpha ProTec Plus boilers, 0A5 indicates a fan speed fault — flue or ventilation issue.
High
Engineer
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1
Ignition Failure
The boiler has failed to ignite. Possible causes include gas supply issues, defective ignition electrode, faulty…
Medium
DIY
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12
Cylinder Sensor Fault (FlowSmart)
The cylinder temperature sensor has a wiring fault or has failed. Relevant on FlowSmart system boilers…
Medium
Engineer
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15
Internal Wiring Error
An incorrect wiring configuration has been detected internally. Usually only occurs after maintenance or installation work.
High
Engineer
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16
Fan Fault
The fan has a fault — either a wiring connection issue, a failed fan motor, or…
High
Engineer
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2
Overheat Boiler Lockout
The boiler has overheated and locked out. Caused by pump or flow problems, blocked heat exchanger,…
High
Engineer
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20
Flame Sensing Fault
The flame sensing electrode is not detecting the flame correctly, or there is a PCB fault…
Medium
Engineer
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24
Control Panel Button Fault
A control panel button is stuck in the ON position, or there is a fault with…
Medium
Engineer
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25
Overheat Lockout (Secondary)
A secondary overheat lockout triggered by air in the heat exchanger, blocked flow, flue restriction, or…
High
Engineer
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27
Insufficient Primary Flow
The boiler is not detecting adequate water flow through the primary circuit. Caused by blockage, restricted…
Medium
Engineer
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29
Flue Sensor Fault
The flue gas temperature sensor has a wiring fault or has failed.
Medium
Engineer
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3
High Flue Temperature
The flue gas temperature has reached a dangerous level. Usually caused by a blocked or restricted…
High
Engineer
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31
Loss of Communication with External Control
The boiler has lost communication with the Alpha Climatic remote control system.
Low
Engineer
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37
Low Supply Voltage
The mains power supply voltage has dropped below the minimum operating level for the boiler.
Medium
Engineer
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38
Loss of Flame Rectification (Type 1)
The boiler's flame rectification circuit has detected a fault with the flame — the electrode may…
Medium
Engineer
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4
Gas Valve Electrical Connection Fault
There is an electrical connection fault at the gas valve — either the valve lead connection…
High
Engineer
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43
Loss of Flame Rectification (Type 2)
Persistent flame rectification loss — similar to code 38 but indicating a more established problem with…
Medium
Engineer
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44
Safety Lockout — External Control Cycling
The boiler has locked out due to too many rapid on/off requests from an external control…
Medium
DIY
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46
External Sensor Fault
The optional external temperature sensor (for weather compensation) has a wiring fault or has failed.
Low
Engineer
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47
Reduced Burner Output — Flue Thermostat Active
The flue thermostat has sensed high flue gas temperature and reduced the burner output as protection.…
Medium
Engineer
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49
Return Sensor High Temperature
The return sensor has detected an unusually high temperature on the heat exchanger return circuit, indicating…
Medium
Engineer
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5
Heating Flow Sensor Fault
The central heating flow temperature sensor has a wiring fault or the sensor itself has failed.
Medium
Engineer
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51
Climatic RF Communication Fault
The wireless communication between the boiler and the Alpha Climatic remote control transmitter has failed. Could…
Low
DIY
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6
DHW Sensor Fault
The domestic hot water temperature sensor has a wiring fault or has failed. Relevant on combi…
Medium
Engineer
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60
Pump Error (E-Tec / Evoke)
On Alpha E-Tec and Evoke combi boilers, code 60 indicates the pump is stuck or has…
High
Engineer
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61
Air in Pump / Restricted CH Flow (E-Tec / Evoke)
On Alpha E-Tec and Evoke boilers, code 61 indicates air in the circulation pump or restricted…
Medium
DIY
View Guide
70
Return/Flow Sensor Wiring Fault (E-Tec)
On Alpha E-Tec boilers, code 70 indicates a wiring or connection issue with the return or…
Medium
Engineer
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71
No Primary Temperature Rise Detected (E-Tec Regular)
After ignition, the boiler has not detected a temperature rise in the primary circuit — indicating…
High
Engineer
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8
Maximum Number of Resets Exceeded
The boiler has reached its maximum reset count. Refer to the fault history codes to identify…
High
Engineer
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E01
Ignition Failure
The boiler has failed to ignite — the burner attempted to light but no flame was…
Medium
DIY
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E02
Flame Supervision Fault
The flame supervision device has detected a problem.
High
Engineer
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E04
High Limit Thermostat Tripped
The high-limit (STB) safety thermostat has activated due to excessive temperature, cutting the gas supply.
High
Engineer
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E05
Return Sensor Fault
The return temperature sensor (NTC thermistor) has failed or has a wiring fault.
Medium
Engineer
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E06
Flue Sensor Fault
The flue gas temperature sensor is giving an out-of-range reading.
Medium
Engineer
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E07
Overheat Sensor Tripped
The main overheat safety sensor (STB) has activated due to excessive boiler temperature.
High
Engineer
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E08
Flue Overheat Sensor Tripped
The flue temperature sensor has detected dangerously high exhaust temperatures.
High
Engineer
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E09
Fan Fault — No Air Pressure
The fan has not generated sufficient air pressure for the air pressure switch to confirm safe…
High
Engineer
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E10
Low Water Pressure
The system water pressure has dropped below 0.6 bar — the minimum required for an Alpha…
Low
DIY
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E11
Return Temperature Too High
The return temperature from the heating circuit is higher than expected, indicating possible circulation issues.
Medium
Engineer
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E14
Pressure Sensor Fault
The electronic water pressure sensor is faulty.
Medium
Engineer
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E15
Low Gas Pressure
The gas supply pressure at the boiler is below the minimum operating threshold.
High
Engineer
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E16
Maximum Temperature Exceeded
The boiler water temperature has exceeded its absolute maximum limit.
High
Engineer
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E20
Flame Failure / No Flame Detected
The boiler cannot detect a flame. The burner has failed to light or the ionisation electrode…
Medium
Engineer
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E25
Dry Fire / Low Water Detected
The boiler has attempted to fire without detecting sufficient water flow, indicating very low water pressure…
High
Engineer
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E28
Flue Fault
There is a problem with the flue — it may be blocked, incorrectly installed, or the…
High
Engineer
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E29
Flow/Return Differential Fault
Temperature gap between flow and return is abnormal.
Medium
Engineer
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E30
Diverter Valve Fault
The diverter valve (which switches flow between heating and hot water on a combi boiler) is…
Medium
Engineer
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E34
Overheat Lockout
The boiler has reached an unsafe temperature and the overheat thermostat has triggered a lockout.
High
Engineer
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E40
False Flame Detected
An ionisation signal has been detected when no flame should be present.
High
Engineer
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E44
Flame Detected After Shutdown
Flame signal present with gas valve closed.
High
Engineer
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E50
DHW Sensor Fault
The domestic hot water temperature sensor is giving an incorrect reading or has failed.
Medium
Engineer
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E55
Flow Temperature Overheat
The flow temperature is excessively high, causing a protective lockout.
High
Engineer
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E60
Fan Fault
The fan is not operating at the required speed or has stopped working.
High
Engineer
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E70
Chip Card / Configuration Error
The boiler's configuration chip card is not reading correctly or has not been properly installed.
Medium
Engineer
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E90
Pressure Switch Fault
The air pressure switch is not registering correctly — this switch confirms that the fan is…
High
Engineer
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E96
Gas Valve Fault
The gas valve has an electronic fault and is not operating correctly.
High
Engineer
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SR
Service Reminder (E-Tec)
Not a fault — this is a service reminder on Alpha E-Tec boilers, indicating the service…
Low
DIY
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