Elnur
Elnur 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 start; display shows E01 and heating/hot water demand is not met.
Flow Switch / Flow Sensor Fault
E02
Boiler locks out with E02; no heating or hot water, internal overheat light may be on.
High Limit Safety Thermostat Trip (Overheat)
E03
Boiler shows E03 and will not operate; internal temperature reading is abnormal or missing.
Primary NTC Temperature Sensor Fault
E04
Boiler displays E04 and stops; may indicate low water or pressure issue depending on model.
Low Water Pressure / Low Water Level Fault
E05
Boiler shows E05; heating elements do not energise even though there is demand.
Heating Element Circuit Fault
E06
Boiler displays E06; internal electronics appear dead or unstable, or boiler resets intermittently.
Power Supply / PCB Fault
E07
Boiler shows E07; pump symbol may flash and there is no circulation.
Circulation Pump Fault
E08
Boiler displays E08; may indicate DHW (domestic hot water) sensor fault on combi-type electric boilers.
DHW NTC Temperature Sensor Fault
E09
Boiler shows E09; may indicate communication or configuration error on some digital Elnur models.
Configuration / Parameter Error
E10
Boiler displays E10; may indicate sensor out-of-range or internal temperature too low/high for normal operation.
Temperature Out-of-Range / Sensor Calibration Fault
E11
Boiler shows E11; may indicate earth leakage or insulation fault on heating elements.
Earth Leakage / Insulation Fault
E12
Boiler displays E12; may indicate internal communication error between display module and main PCB.
Display–Main PCB Communication Fault
E13
Boiler shows E13; may indicate external thermostat or control input fault.
External Control Circuit Fault
E14
Boiler displays E14; may indicate sensor short-circuit condition.
Shorted Temperature Sensor
E15
Boiler shows E15; may indicate return temperature sensor fault or differential temperature error.
Return NTC Sensor / Delta-T Fault
E16
Boiler displays E16; may indicate internal memory or software error.
EEPROM / Firmware Fault
E17
Boiler shows E17; may indicate overcurrent or internal protection trip on power stage.
Power Stage Overcurrent / Protection Trip
E18
Boiler displays E18; may indicate incorrect phase configuration on multi-phase Elnur boilers.
Phase Configuration / Phase Loss Fault
E19
Boiler shows E19; may indicate internal clock or timer fault on models with integrated programmer.
Internal Clock / Timer Fault
E20
Boiler displays E20; may indicate safety chain open (e.g., overheat, door, or other safety device open).
Safety Interlock Open
Symptom
Boiler casing or nearby area has a burnt smell during operation.
Overheating Electrical Component
Symptom
Boiler completely dead – no lights or display, no response to controls.
No Power / Supply Failure
Symptom
Boiler cycles on and off rapidly, with short run times and frequent starts.
Short Cycling
Symptom
Boiler display works but buttons or controls do not respond properly.
User Interface / Keypad Fault
Symptom
Boiler does not respond to room thermostat; heating stays on or off regardless of setting.
Control Signal Failure
Symptom
Boiler frequently shows air in system; gurgling noises from radiators and boiler.
Persistent Air Ingress
Symptom
Boiler frequently trips the main breaker or RCD when heating starts.
Nuisance Tripping / Overcurrent
Symptom
Boiler heats but radiators only get lukewarm; system struggles to reach set temperature.
Insufficient Heating Output
Symptom
Boiler loses pressure over time (sealed systems) and needs frequent topping up.
System Pressure Loss
Symptom
Boiler or connected pipework vibrates excessively when heating is on.
Hydraulic Vibration / Water Hammer
Symptom
Boiler powers on but does not heat radiators; flow and return pipes remain cold.
No Heating Output
Symptom
Boiler pressure (on sealed systems) rises rapidly when heating and may discharge through safety valve.
Over-Pressurisation
Symptom
Boiler runs but makes loud humming or grinding noises from inside the casing.
Mechanical Noise from Pump or Components
Symptom
Boiler trips its internal manual reset thermostat occasionally but then works again after reset.
Intermittent Overheat
Symptom
Domestic hot water temperature fluctuates or is not hot enough (on Elnur systems providing DHW).
Unstable DHW Temperature
Symptom
Radiators heat unevenly; some remain cold while others are hot.
Poor Circulation / System Imbalance
Symptom
Water leak visible from the bottom of the boiler casing.
Internal Water Leak
| Error Code | Symptom | Fault Type | Guide |
|---|---|---|---|
| E01 |
Boiler does not start; display shows E01 and heating/hot water demand is not met.
|
Flow Switch / Flow Sensor Fault | View Details |
| E02 |
Boiler locks out with E02; no heating or hot water, internal overheat light may be on.
|
High Limit Safety Thermostat Trip (Overheat) | View Details |
| E03 |
Boiler shows E03 and will not operate; internal temperature reading is abnormal or missing.
|
Primary NTC Temperature Sensor Fault | View Details |
| E04 |
Boiler displays E04 and stops; may indicate low water or pressure issue depending on model.
|
Low Water Pressure / Low Water Level Fault | View Details |
| E05 |
Boiler shows E05; heating elements do not energise even though there is demand.
|
Heating Element Circuit Fault | View Details |
| E06 |
Boiler displays E06; internal electronics appear dead or unstable, or boiler resets intermittently.
|
Power Supply / PCB Fault | View Details |
| E07 |
Boiler shows E07; pump symbol may flash and there is no circulation.
|
Circulation Pump Fault | View Details |
| E08 |
Boiler displays E08; may indicate DHW (domestic hot water) sensor fault on combi-type electric boilers.
|
DHW NTC Temperature Sensor Fault | View Details |
| E09 |
Boiler shows E09; may indicate communication or configuration error on some digital Elnur models.
|
Configuration / Parameter Error | View Details |
| E10 |
Boiler displays E10; may indicate sensor out-of-range or internal temperature too low/high for normal operation.
|
Temperature Out-of-Range / Sensor Calibration Fault | View Details |
| E11 |
Boiler shows E11; may indicate earth leakage or insulation fault on heating elements.
|
Earth Leakage / Insulation Fault | View Details |
| E12 |
Boiler displays E12; may indicate internal communication error between display module and main PCB.
|
Display–Main PCB Communication Fault | View Details |
| E13 |
Boiler shows E13; may indicate external thermostat or control input fault.
|
External Control Circuit Fault | View Details |
| E14 |
Boiler displays E14; may indicate sensor short-circuit condition.
|
Shorted Temperature Sensor | View Details |
| E15 |
Boiler shows E15; may indicate return temperature sensor fault or differential temperature error.
|
Return NTC Sensor / Delta-T Fault | View Details |
| E16 |
Boiler displays E16; may indicate internal memory or software error.
|
EEPROM / Firmware Fault | View Details |
| E17 |
Boiler shows E17; may indicate overcurrent or internal protection trip on power stage.
|
Power Stage Overcurrent / Protection Trip | View Details |
| E18 |
Boiler displays E18; may indicate incorrect phase configuration on multi-phase Elnur boilers.
|
Phase Configuration / Phase Loss Fault | View Details |
| E19 |
Boiler shows E19; may indicate internal clock or timer fault on models with integrated programmer.
|
Internal Clock / Timer Fault | View Details |
| E20 |
Boiler displays E20; may indicate safety chain open (e.g., overheat, door, or other safety device open).
|
Safety Interlock Open | View Details |
| – |
Boiler casing or nearby area has a burnt smell during operation.
|
Overheating Electrical Component | View Details |
| – |
Boiler completely dead – no lights or display, no response to controls.
|
No Power / Supply Failure | View Details |
| – |
Boiler cycles on and off rapidly, with short run times and frequent starts.
|
Short Cycling | View Details |
| – |
Boiler display works but buttons or controls do not respond properly.
|
User Interface / Keypad Fault | View Details |
| – |
Boiler does not respond to room thermostat; heating stays on or off regardless of setting.
|
Control Signal Failure | View Details |
| – |
Boiler frequently shows air in system; gurgling noises from radiators and boiler.
|
Persistent Air Ingress | View Details |
| – |
Boiler frequently trips the main breaker or RCD when heating starts.
|
Nuisance Tripping / Overcurrent | View Details |
| – |
Boiler heats but radiators only get lukewarm; system struggles to reach set temperature.
|
Insufficient Heating Output | View Details |
| – |
Boiler loses pressure over time (sealed systems) and needs frequent topping up.
|
System Pressure Loss | View Details |
| – |
Boiler or connected pipework vibrates excessively when heating is on.
|
Hydraulic Vibration / Water Hammer | View Details |
| – |
Boiler powers on but does not heat radiators; flow and return pipes remain cold.
|
No Heating Output | View Details |
| – |
Boiler pressure (on sealed systems) rises rapidly when heating and may discharge through safety valve.
|
Over-Pressurisation | View Details |
| – |
Boiler runs but makes loud humming or grinding noises from inside the casing.
|
Mechanical Noise from Pump or Components | View Details |
| – |
Boiler trips its internal manual reset thermostat occasionally but then works again after reset.
|
Intermittent Overheat | View Details |
| – |
Domestic hot water temperature fluctuates or is not hot enough (on Elnur systems providing DHW).
|
Unstable DHW Temperature | View Details |
| – |
Radiators heat unevenly; some remain cold while others are hot.
|
Poor Circulation / System Imbalance | View Details |
| – |
Water leak visible from the bottom of the boiler casing.
|
Internal Water Leak | View Details |
No matching codes found
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