Vokera
Vokera Boilers Error Codes
Complete list of fault codes and troubleshooting guides. Use the search below to find your specific error.
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01
Boiler will not ignite, display shows fault code 01, no heating or hot water
Ignition Failure / Flame Not Detected
02
Boiler locks out with code 02, fan runs but no ignition, or ignition stops quickly
Flame Detection Failure / Flame Signal Lost
03
Boiler shows 03 and shuts down, fan may not start, no ignition sequence
Fan / Air Pressure Switch Fault
04
Boiler displays 04 and locks out, no heating or hot water
Ignition Lockout / Repeated Failed Starts
05
Boiler displays 05, will not fire, may attempt ignition then shut down.
Overheat Thermostat Tripped
06
Boiler displays 06; temperature rises rapidly then locks out.
Flow Temperature Sensor Fault / Overheat Detection
07
Boiler displays 07, may run briefly then shut down, and temperature readings are erratic.
Return Temperature Sensor Fault
08
Boiler displays 08; no heating or hot water, which may indicate a flue or air fault.
Air Pressure Switch / Flue System Fault
09
Boiler displays 09; the fan runs continuously or not at all, and there is no ignition.
Fan Speed / Fan Feedback Fault
10
Boiler displays 10; no heating or hot water, which may indicate a flue or ventilation issue.
Flue Gas Safety / Combustion Fault
11
Boiler displays 11, will not start, and may indicate low water pressure or a circulation fault.
Low System Pressure / Water Circulation Fault
12
Boiler displays 12; heating demand is not recognized, or the boiler cycles rapidly.
Flow Switch / Flow Sensor Fault (DHW or CH depending on model)
13
Boiler displays 13; temperature readings are unstable, and the boiler may short-cycle.
Domestic Hot Water NTC Sensor Fault
20
Boiler displays 20; there is no response to the thermostat, and heating will not start.
External Control / Room Thermostat Circuit Fault
23
Boiler displays error code 23, which may indicate a pump or circulation fault, or overheating on the flow.
Pump Fault / Insufficient Circulation
24
Boiler displays error code 24; the pressure gauge may be high, and water may be discharged from the PRV.
High System Pressure / Expansion Vessel Fault
25
Boiler displays error code 25, resulting in no heating, which may indicate a sensor or PCB fault.
General Temperature Sensor / PCB Fault
27
Boiler displays error code 27, indicating intermittent lockouts, which may relate to the ionization/flame signal.
Flame Signal Instability
40
Boiler displays error code 40, resulting in no heating or hot water, which may indicate a lockout due to repeated faults.
General Lockout / Multiple Fault Condition
A01
Vokera boiler (e.g., Compact, Easi-Heat, Vision) displays error code A01, indicating no flame detected.
Ignition Failure (Modern Alpha Code)
A02
Boiler displays error code A02, indicating an overheat condition; the boiler becomes very hot and then shuts down.
Primary Circuit Overheat
A03
Boiler displays error code A03, indicating a fan/flue related fault, resulting in no ignition.
Flue Fan / Air Pressure Fault (Alpha Code)
A04
Boiler displays error code A04, indicating low water pressure and no heating.
Low System Pressure (Alpha Code)
A06
Boiler displays error code A06, indicating an NTC sensor fault; the boiler may not fire.
Flow or Return NTC Sensor Error (Alpha Code)
A07
Boiler displays A07, indicating a DHW temperature sensor fault, leading to unstable hot water temperature.
DHW NTC Sensor Error (Alpha Code)
A08
Boiler displays A08, indicating a pump or circulation-related fault, which may cause it to overheat quickly.
Pump / Circulation Fault (Alpha Code)
A09
Boiler displays A09, indicating flue gas over-temperature or a flue sensor fault (on models fitted).
Flue Gas Temperature Fault
Symptom
Boiler frequently loses pressure and needs topping up every few days.
Chronic Pressure Loss
Symptom
Boiler leaking water from underneath the casing or pipe connections.
Internal Water Leak
Symptom
Boiler makes loud banging or kettling noises during operation, especially when heating.
Kettling / Localised Boiling in Heat Exchanger
Symptom
Boiler makes loud humming, vibrating, or rattling noises during operation.
Mechanical Vibration / Resonance
Symptom
Boiler or flue emits unusual smells (burning, metallic, or exhaust-like odor).
Combustion / Overheating Smell
Symptom
Boiler provides hot water, but central heating does not come on, even though the thermostat is calling.
No Central Heating Demand / Diverter Valve Stuck
Symptom
Boiler randomly turns off and on, or cuts out before reaching the set temperature.
Short Cycling / Intermittent Operation
Symptom
Boiler runs for central heating but does not provide any hot water at the taps.
No Domestic Hot Water on Combi Boiler
Symptom
Boiler will not start at all; no lights or display.
No Power / Dead Boiler
Symptom
Condensate water dripping from the bottom of the boiler casing or flue joints.
Condensate Drain / Trap Issue
Symptom
Hot water temperature fluctuates between hot and cold when using a tap or shower.
Inconsistent Domestic Hot Water Temperature
Symptom
Radiators only get warm at the bottom, or some radiators stay cold while the boiler runs.
Poor Heating Circulation / Sludge Build-up
Symptom
The boiler display is on, but it does not respond to controls or buttons.
User Interface / Control Panel Fault
Symptom
The boiler locks out more often during very cold weather, affecting external pipework.
Frozen Condensate Pipe
| Error Code | Symptom | Fault Type | Guide |
|---|---|---|---|
| 01 |
Boiler will not ignite, display shows fault code 01, no heating or hot water
|
Ignition Failure / Flame Not Detected | View Details |
| 02 |
Boiler locks out with code 02, fan runs but no ignition, or ignition stops quickly
|
Flame Detection Failure / Flame Signal Lost | View Details |
| 03 |
Boiler shows 03 and shuts down, fan may not start, no ignition sequence
|
Fan / Air Pressure Switch Fault | View Details |
| 04 |
Boiler displays 04 and locks out, no heating or hot water
|
Ignition Lockout / Repeated Failed Starts | View Details |
| 05 |
Boiler displays 05, will not fire, may attempt ignition then shut down.
|
Overheat Thermostat Tripped | View Details |
| 06 |
Boiler displays 06; temperature rises rapidly then locks out.
|
Flow Temperature Sensor Fault / Overheat Detection | View Details |
| 07 |
Boiler displays 07, may run briefly then shut down, and temperature readings are erratic.
|
Return Temperature Sensor Fault | View Details |
| 08 |
Boiler displays 08; no heating or hot water, which may indicate a flue or air fault.
|
Air Pressure Switch / Flue System Fault | View Details |
| 09 |
Boiler displays 09; the fan runs continuously or not at all, and there is no ignition.
|
Fan Speed / Fan Feedback Fault | View Details |
| 10 |
Boiler displays 10; no heating or hot water, which may indicate a flue or ventilation issue.
|
Flue Gas Safety / Combustion Fault | View Details |
| 11 |
Boiler displays 11, will not start, and may indicate low water pressure or a circulation fault.
|
Low System Pressure / Water Circulation Fault | View Details |
| 12 |
Boiler displays 12; heating demand is not recognized, or the boiler cycles rapidly.
|
Flow Switch / Flow Sensor Fault (DHW or CH depending on model) | View Details |
| 13 |
Boiler displays 13; temperature readings are unstable, and the boiler may short-cycle.
|
Domestic Hot Water NTC Sensor Fault | View Details |
| 20 |
Boiler displays 20; there is no response to the thermostat, and heating will not start.
|
External Control / Room Thermostat Circuit Fault | View Details |
| 23 |
Boiler displays error code 23, which may indicate a pump or circulation fault, or overheating on the flow.
|
Pump Fault / Insufficient Circulation | View Details |
| 24 |
Boiler displays error code 24; the pressure gauge may be high, and water may be discharged from the PRV.
|
High System Pressure / Expansion Vessel Fault | View Details |
| 25 |
Boiler displays error code 25, resulting in no heating, which may indicate a sensor or PCB fault.
|
General Temperature Sensor / PCB Fault | View Details |
| 27 |
Boiler displays error code 27, indicating intermittent lockouts, which may relate to the ionization/flame signal.
|
Flame Signal Instability | View Details |
| 40 |
Boiler displays error code 40, resulting in no heating or hot water, which may indicate a lockout due to repeated faults.
|
General Lockout / Multiple Fault Condition | View Details |
| A01 |
Vokera boiler (e.g., Compact, Easi-Heat, Vision) displays error code A01, indicating no flame detected.
|
Ignition Failure (Modern Alpha Code) | View Details |
| A02 |
Boiler displays error code A02, indicating an overheat condition; the boiler becomes very hot and then shuts down.
|
Primary Circuit Overheat | View Details |
| A03 |
Boiler displays error code A03, indicating a fan/flue related fault, resulting in no ignition.
|
Flue Fan / Air Pressure Fault (Alpha Code) | View Details |
| A04 |
Boiler displays error code A04, indicating low water pressure and no heating.
|
Low System Pressure (Alpha Code) | View Details |
| A06 |
Boiler displays error code A06, indicating an NTC sensor fault; the boiler may not fire.
|
Flow or Return NTC Sensor Error (Alpha Code) | View Details |
| A07 |
Boiler displays A07, indicating a DHW temperature sensor fault, leading to unstable hot water temperature.
|
DHW NTC Sensor Error (Alpha Code) | View Details |
| A08 |
Boiler displays A08, indicating a pump or circulation-related fault, which may cause it to overheat quickly.
|
Pump / Circulation Fault (Alpha Code) | View Details |
| A09 |
Boiler displays A09, indicating flue gas over-temperature or a flue sensor fault (on models fitted).
|
Flue Gas Temperature Fault | View Details |
| – |
Boiler frequently loses pressure and needs topping up every few days.
|
Chronic Pressure Loss | View Details |
| – |
Boiler leaking water from underneath the casing or pipe connections.
|
Internal Water Leak | View Details |
| – |
Boiler makes loud banging or kettling noises during operation, especially when heating.
|
Kettling / Localised Boiling in Heat Exchanger | View Details |
| – |
Boiler makes loud humming, vibrating, or rattling noises during operation.
|
Mechanical Vibration / Resonance | View Details |
| – |
Boiler or flue emits unusual smells (burning, metallic, or exhaust-like odor).
|
Combustion / Overheating Smell | View Details |
| – |
Boiler provides hot water, but central heating does not come on, even though the thermostat is calling.
|
No Central Heating Demand / Diverter Valve Stuck | View Details |
| – |
Boiler randomly turns off and on, or cuts out before reaching the set temperature.
|
Short Cycling / Intermittent Operation | View Details |
| – |
Boiler runs for central heating but does not provide any hot water at the taps.
|
No Domestic Hot Water on Combi Boiler | View Details |
| – |
Boiler will not start at all; no lights or display.
|
No Power / Dead Boiler | View Details |
| – |
Condensate water dripping from the bottom of the boiler casing or flue joints.
|
Condensate Drain / Trap Issue | View Details |
| – |
Hot water temperature fluctuates between hot and cold when using a tap or shower.
|
Inconsistent Domestic Hot Water Temperature | View Details |
| – |
Radiators only get warm at the bottom, or some radiators stay cold while the boiler runs.
|
Poor Heating Circulation / Sludge Build-up | View Details |
| – |
The boiler display is on, but it does not respond to controls or buttons.
|
User Interface / Control Panel Fault | View Details |
| – |
The boiler locks out more often during very cold weather, affecting external pipework.
|
Frozen Condensate Pipe | View Details |
No matching codes found
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