Termet
Termet Boilers Error Codes
Complete list of fault codes and troubleshooting guides. Use the search below to find your specific error.
Advertisements
E01
Boiler does not ignite, display shows E01, no flame symbol, heating and hot water unavailable.
Ignition Failure / No Flame Detection
E02
Boiler locks out with E02, burner stops shortly after ignition or during operation, possible overheating sensation on casing.
Overheat Thermostat Tripped / Safety Temperature Limiter
E03
Boiler displays E03 and shuts down, fan may start briefly then stop, no ignition attempt.
Flue Gas Safety / Flue Gas Thermostat or Draft Fault
E04
Boiler shows E04, no ignition, fan may run, sometimes accompanied by gurgling sounds in the flue.
Air Pressure Switch / Fan Pressure Fault
E05
Boiler displays E05, heating does not start, temperature reading may be unrealistic or fixed.
Flow Temperature Sensor (CH NTC) Fault
E06
Boiler shows E06, domestic hot water (DHW) does not heat, DHW temperature reading is incorrect or unstable.
DHW Temperature Sensor (DHW NTC) Fault
E07
Boiler locks out with E07, no heating or hot water, may occur after power surge or wiring work.
Flow Sensor / Flow Switch Fault (Hydraulic Sensor)
E08
Boiler shows E08, burner stops, pump may continue to run, temperature rises quickly on display.
Insufficient Circulation / Pump Fault
E09
Boiler displays E09, no ignition, may occur immediately after start-up or after service work.
Gas Valve / Gas Supply Fault
E10
Boiler shows E10, heating and hot water disabled, pressure gauge indicates low or zero pressure.
Low Water Pressure / System Pressure Fault
E11
Boiler intermittently locks out with E11, especially during hot water use, sometimes with fluctuating temperatures.
DHW Flow Switch / Turbine Fault
E12
Boiler shows E12, no response to thermostat demand, display may indicate communication error.
Room Thermostat / Control Communication Fault
E13
Boiler displays E13, fan may run at high speed, no ignition, often after flue modifications.
Fan Speed / Combustion Control Fault
E14
Boiler shows E14, may ignite briefly then shut down, flame symbol flickers.
Flame Loss During Operation
E15
Boiler displays E15, temperature readings jump or are inconsistent, boiler may cycle rapidly.
Return Temperature Sensor (Return NTC) Fault
E16
Boiler shows E16, no heating, pump may run continuously, sometimes after power disturbances.
Internal PCB Error / Configuration Fault
E17
Boiler intermittently shows E17, especially when switching between CH and DHW, with unstable temperatures.
Three-Way Valve Positioning Fault
E18
Boiler shows E18, no ignition, may be accompanied by fan running and then stopping.
Exhaust / Intake Sensor Fault (if fitted)
E19
Boiler displays E19, may continue to run at reduced performance, error appears intermittently.
Modulation / Gas Valve Control Fault
E20
Boiler shows E20, no operation, may be accompanied by other error codes or display anomalies.
Power Supply / Low Voltage Fault
Symptom
Boiler display is on but unresponsive to button presses or rotary controls, heating and hot water may continue in last mode.
Control Panel / User Interface Failure
Symptom
Boiler does not start at all, no display or lights, as if completely dead.
No Power / Electrical Supply Failure
Symptom
Boiler emits a burning smell or plastic odour during operation, sometimes with slight smoke from casing vents.
Overheating Electrical Component / Insulation Damage
Symptom
Boiler fan runs continuously even when there is no demand for heating or hot water.
Fan Overrun / Stuck Relay or Sensor Misread
Symptom
Boiler frequently loses pressure over days or weeks, requiring regular topping up, but no obvious leaks are visible.
Chronic Pressure Loss / Expansion Vessel Failure
Symptom
Boiler frequently needs manual resetting to restore operation, with varying minor error indications or none at all.
Intermittent Lockout / General Instability
Symptom
Boiler frequently short cycles (turns on and off rapidly) during heating, with noticeable wear noises.
Short Cycling / Oversized Boiler or Control Issue
Symptom
Boiler leaking water from underneath the casing or from pipe connections, no specific error code displayed.
Internal Water Leak / Hydraulic Seal Failure
Symptom
Boiler locks out occasionally without a clear error code, often during windy conditions, then restarts after reset.
Wind-Induced Flue Disturbance / Flame Instability
Symptom
Boiler makes loud banging or knocking noises (kettling) during operation, especially on central heating demand.
Heat Exchanger Kettling / Localised Boiling
Symptom
Boiler produces a strong smell of gas near the appliance, with or without operation.
Gas Leak at Boiler Connections
Symptom
Boiler runs for central heating but radiators remain cold while hot water works normally.
No Central Heating / Diverter Valve Stuck in DHW Position
Symptom
Boiler runs for hot water but tap temperature is only lukewarm even at low flow.
Reduced DHW Output / Heat Transfer Limitation
Symptom
Boiler vibrates excessively or resonates through the flue and pipework during operation.
Mechanical Vibration / Fan or Pump Imbalance
Symptom
Hot water temperature fluctuates between hot and cold during shower use, without any error code.
Unstable DHW Temperature / Flow Modulation Issue
Symptom
Radiators are only lukewarm and the house does not reach the set temperature, boiler cycles on and off frequently.
Insufficient Heating Output / System Balancing Issue
| Error Code | Symptom | Fault Type | Guide |
|---|---|---|---|
| E01 |
Boiler does not ignite, display shows E01, no flame symbol, heating and hot water unavailable.
|
Ignition Failure / No Flame Detection | View Details |
| E02 |
Boiler locks out with E02, burner stops shortly after ignition or during operation, possible overheating sensation on casing.
|
Overheat Thermostat Tripped / Safety Temperature Limiter | View Details |
| E03 |
Boiler displays E03 and shuts down, fan may start briefly then stop, no ignition attempt.
|
Flue Gas Safety / Flue Gas Thermostat or Draft Fault | View Details |
| E04 |
Boiler shows E04, no ignition, fan may run, sometimes accompanied by gurgling sounds in the flue.
|
Air Pressure Switch / Fan Pressure Fault | View Details |
| E05 |
Boiler displays E05, heating does not start, temperature reading may be unrealistic or fixed.
|
Flow Temperature Sensor (CH NTC) Fault | View Details |
| E06 |
Boiler shows E06, domestic hot water (DHW) does not heat, DHW temperature reading is incorrect or unstable.
|
DHW Temperature Sensor (DHW NTC) Fault | View Details |
| E07 |
Boiler locks out with E07, no heating or hot water, may occur after power surge or wiring work.
|
Flow Sensor / Flow Switch Fault (Hydraulic Sensor) | View Details |
| E08 |
Boiler shows E08, burner stops, pump may continue to run, temperature rises quickly on display.
|
Insufficient Circulation / Pump Fault | View Details |
| E09 |
Boiler displays E09, no ignition, may occur immediately after start-up or after service work.
|
Gas Valve / Gas Supply Fault | View Details |
| E10 |
Boiler shows E10, heating and hot water disabled, pressure gauge indicates low or zero pressure.
|
Low Water Pressure / System Pressure Fault | View Details |
| E11 |
Boiler intermittently locks out with E11, especially during hot water use, sometimes with fluctuating temperatures.
|
DHW Flow Switch / Turbine Fault | View Details |
| E12 |
Boiler shows E12, no response to thermostat demand, display may indicate communication error.
|
Room Thermostat / Control Communication Fault | View Details |
| E13 |
Boiler displays E13, fan may run at high speed, no ignition, often after flue modifications.
|
Fan Speed / Combustion Control Fault | View Details |
| E14 |
Boiler shows E14, may ignite briefly then shut down, flame symbol flickers.
|
Flame Loss During Operation | View Details |
| E15 |
Boiler displays E15, temperature readings jump or are inconsistent, boiler may cycle rapidly.
|
Return Temperature Sensor (Return NTC) Fault | View Details |
| E16 |
Boiler shows E16, no heating, pump may run continuously, sometimes after power disturbances.
|
Internal PCB Error / Configuration Fault | View Details |
| E17 |
Boiler intermittently shows E17, especially when switching between CH and DHW, with unstable temperatures.
|
Three-Way Valve Positioning Fault | View Details |
| E18 |
Boiler shows E18, no ignition, may be accompanied by fan running and then stopping.
|
Exhaust / Intake Sensor Fault (if fitted) | View Details |
| E19 |
Boiler displays E19, may continue to run at reduced performance, error appears intermittently.
|
Modulation / Gas Valve Control Fault | View Details |
| E20 |
Boiler shows E20, no operation, may be accompanied by other error codes or display anomalies.
|
Power Supply / Low Voltage Fault | View Details |
| – |
Boiler display is on but unresponsive to button presses or rotary controls, heating and hot water may continue in last mode.
|
Control Panel / User Interface Failure | View Details |
| – |
Boiler does not start at all, no display or lights, as if completely dead.
|
No Power / Electrical Supply Failure | View Details |
| – |
Boiler emits a burning smell or plastic odour during operation, sometimes with slight smoke from casing vents.
|
Overheating Electrical Component / Insulation Damage | View Details |
| – |
Boiler fan runs continuously even when there is no demand for heating or hot water.
|
Fan Overrun / Stuck Relay or Sensor Misread | View Details |
| – |
Boiler frequently loses pressure over days or weeks, requiring regular topping up, but no obvious leaks are visible.
|
Chronic Pressure Loss / Expansion Vessel Failure | View Details |
| – |
Boiler frequently needs manual resetting to restore operation, with varying minor error indications or none at all.
|
Intermittent Lockout / General Instability | View Details |
| – |
Boiler frequently short cycles (turns on and off rapidly) during heating, with noticeable wear noises.
|
Short Cycling / Oversized Boiler or Control Issue | View Details |
| – |
Boiler leaking water from underneath the casing or from pipe connections, no specific error code displayed.
|
Internal Water Leak / Hydraulic Seal Failure | View Details |
| – |
Boiler locks out occasionally without a clear error code, often during windy conditions, then restarts after reset.
|
Wind-Induced Flue Disturbance / Flame Instability | View Details |
| – |
Boiler makes loud banging or knocking noises (kettling) during operation, especially on central heating demand.
|
Heat Exchanger Kettling / Localised Boiling | View Details |
| – |
Boiler produces a strong smell of gas near the appliance, with or without operation.
|
Gas Leak at Boiler Connections | View Details |
| – |
Boiler runs for central heating but radiators remain cold while hot water works normally.
|
No Central Heating / Diverter Valve Stuck in DHW Position | View Details |
| – |
Boiler runs for hot water but tap temperature is only lukewarm even at low flow.
|
Reduced DHW Output / Heat Transfer Limitation | View Details |
| – |
Boiler vibrates excessively or resonates through the flue and pipework during operation.
|
Mechanical Vibration / Fan or Pump Imbalance | View Details |
| – |
Hot water temperature fluctuates between hot and cold during shower use, without any error code.
|
Unstable DHW Temperature / Flow Modulation Issue | View Details |
| – |
Radiators are only lukewarm and the house does not reach the set temperature, boiler cycles on and off frequently.
|
Insufficient Heating Output / System Balancing Issue | View Details |
No matching codes found
Advertisements