Vokèra Boiler Fault Codes: Error Codes & What They Mean

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Updated:

Vokèra boiler fault code showing? The code is designed to help identify what part of the boiler’s operation has gone wrong, but the meaning depends on your exact Vokèra model.
Older Vokèra boilers can use codes such as A01, A02 and A04, while newer boilers may display A10, A40 or E-series codes such as E010 and E040.
For that reason, always identify your boiler model before using a fault-code table. The code is a diagnostic clue, not proof that a particular component needs replacing.
Before searching for a repair, make a note of:
Vokèra has produced several generations of boilers with different controls and error-code systems, so the same number should not automatically be applied to every model.
The following table covers common fault groups found across several Vokèra ranges. Always check the manual for your exact boiler before acting on a code.
| Fault code | Typical meaning | What to do |
|---|---|---|
| A01 / A10 / E010 | Ignition or flame lockout on relevant models | Check basic gas supply and reset only as instructed. Call an engineer if it returns. |
| A02 / A20 / E020 | High-limit thermostat or overheat fault | Do not repeatedly reset. Circulation or overheating needs investigation if recurring. |
| A03 / A30 / E030 | Fan-related fault | Professional diagnosis required. |
| A04 / A40 / E040 | Low heating-system water pressure on relevant models | Check the pressure and follow the correct model instructions if filling is required. |
| A42 / E042 | Water-pressure sensor or transducer fault | Professional testing normally required. |
| A60 / E060 | Domestic-hot-water sensor/probe fault on relevant models | Engineer diagnosis may be required. |
| A70 / E070 | Flow temperature sensor or related temperature fault | Sensor, wiring and system operation may need checking. |
| A80 / E080 | Return temperature sensor fault on relevant models | Professional diagnosis required. |
| A90 / E090 | Flue-gas/exhaust temperature sensor fault on relevant models | Do not dismantle the boiler or flue. Arrange diagnosis. |
Ignition-related codes vary between Vokèra generations.
For example, some older models use A01, Easi-Heat i documentation uses A10, while newer platforms can use E010.
Depending on the particular model, the fault can involve:
You can check whether another gas appliance works and whether a prepayment meter has credit.
Do not remove the boiler casing, adjust the gas valve or work on ignition components yourself.
If your main symptom is that the boiler will not start, see:
Boiler Not Firing Up? Causes & What to Check
On relevant Vokèra models, these codes relate to the high-limit or safety thermostat.
The boiler may shut down because an unsafe or abnormal temperature condition has been detected.
Possible areas an engineer may consider include:
Do not continually reset an overheating boiler.
If the fault returns, the reason for the excessive temperature needs to be identified.
Different Vokèra generations use different codes for fan-related problems.
For example, older models may show A03 while other ranges use A30 or E030.
The fan forms part of the boiler’s combustion and flue system, so this is not a homeowner repair.
Depending on the exact model, an engineer may need to check:
Low water pressure is one of the most common faults homeowners can identify themselves.
Depending on the Vokèra model, low system pressure may appear as codes such as:
Vokèra commonly recommends around 1 to 1.5 bar on relevant sealed systems, but always follow the instructions for your exact boiler.
If the pressure is genuinely low and your manual explains how to refill the system, you may be able to restore it using the filling arrangement.
For more information, see:
Normal Boiler Pressure & Pressure Adjustment
If you have to keep topping the boiler up, that is more important than the one-off low reading.
See:
Why Does My Boiler Pressure Keep Dropping?
Some Vokèra models distinguish between genuinely low water pressure and a fault with the component measuring that pressure.
This is important because adding more water will not repair a defective pressure sensor.
If the boiler pressure appears normal but a pressure-related error remains, do not continue filling the heating system.
An engineer may need to check the pressure transducer, associated wiring and the actual system pressure.
On relevant Vokèra boilers, A60 or E060 can relate to a domestic-hot-water temperature sensor or probe.
Possible symptoms may include:
The exact interpretation depends on the boiler model, so check the correct Vokèra manual before assuming the sensor itself needs replacing.
If your boiler runs but you have no hot water, also see:
No Hot Water From Boiler? Causes & What to Check
The boiler monitors the temperature of water travelling out through the heating flow and returning to the appliance.
On relevant Vokèra ranges, A70 or E070 relates to the flow temperature sensor, while A80 or E080 can relate to the return sensor.
Depending on the exact model and code, the fault can involve:
The code therefore should not automatically result in a new sensor being fitted without testing.
Some Vokèra models monitor flue-gas temperature using an exhaust or flue-gas sensor.
A90 or E090 can indicate a fault involving that sensor on relevant models.
Some newer Vokèra boilers can also display E091, which can indicate that the primary heat exchanger requires cleaning according to the appliance’s diagnostic system.
These are not homeowner maintenance tasks.
Do not remove the boiler casing or attempt to dismantle or clean combustion components yourself.
Newer Vokèra boiler platforms can use more detailed E-series diagnostics.
Examples found on current Vokèra documentation include:
| Code | Meaning on relevant models |
|---|---|
| E010 | Flame lockout |
| E011 | Unexpected or parasitic flame |
| E012 | Maximum number of flame losses reached |
| E020 | Limit thermostat fault |
| E021 | Gas-valve control malfunction |
| E030 | Fan error |
| E031–E033 | More specific fan or rotor faults |
| E034–E036 | Flue or combustion-air obstruction faults |
| E040 | Low water pressure |
| E042 | Water-pressure transducer fault |
| E060 | Domestic-hot-water probe fault on relevant combi models |
| E070 | Central-heating flow temperature probe fault |
| E080 | Return temperature probe fault |
| E090 | Exhaust/flue-gas temperature probe fault |
| E091 | Primary heat-exchanger cleaning indication on relevant models |
| E099 | Reset attempts exhausted |
This is why the boiler model is essential. Do not use a newer E-series table to diagnose an older Vokèra appliance that uses a different control system.
On relevant newer Vokèra boilers, E040 means the system pressure is too low and the heating system needs filling.
Some models first show a warning or temporary E041 condition before progressing to a permanent E040 lockout.
If the pressure is genuinely low:
If pressure continues falling after you refill the boiler, investigate the reason for the pressure loss rather than continually topping up.
On many Vokèra boilers, a red light indicates a fault or lockout, but the exact meaning depends on the appliance.
Some older boilers use combinations of coloured LEDs rather than a detailed digital error code.
Other boilers display a fault code together with a red warning indication.
If your main symptom is the warning light rather than a readable code, see:
Vokèra Boiler Red Light On: What It Means
Many Vokèra boilers have a normal reset procedure described in their user manual.
You can use that procedure for an appropriate lockout after recording the fault code.
However, resetting does not repair the underlying fault.
If the same error returns, repeatedly resetting the boiler can hide useful diagnostic information and will not repair:
Newer Vokèra documentation can also limit the number of consecutive reset attempts before another lockout is displayed.
Vokèra advises that frequently needing to top up the heating system can indicate a water leak.
Check visible areas such as:
If the pressure keeps falling, see:
Why Does My Boiler Pressure Keep Dropping?
If water is visibly coming from the boiler, see:
Boiler Leaking Water? Causes & What to Do
Before calling an engineer, Vokèra recommends basic checks such as confirming:
If these checks are satisfactory but the boiler remains in ignition lockout, professional diagnosis may be needed.
Some external checks are appropriate for homeowners.
You can usually:
Depending on your model, you may also be able to repressurise the heating system by following the manufacturer’s instructions.
You should not:
A useful diagnosis starts with the exact model and exact code.
An engineer can then combine that information with:
Engineer point: a fault code identifies an abnormal condition or diagnostic area. It should not automatically be treated as an instruction to replace the component named beside the code.
There is no accurate universal repair price because a Vokèra error code can lead to several different diagnoses.
For example, an ignition lockout could ultimately involve:
Likewise, a pressure-related warning could be genuine low water pressure, an ongoing leak or a faulty pressure sensor.
The fault should therefore be diagnosed before a repair price is quoted.
No.
A fault code does not automatically mean the boiler needs replacing.
Many ignition, pressure, sensor, fan and circulation faults can be repaired.
Replacement becomes worth comparing if an older appliance has several significant faults or the confirmed repair is substantial relative to its age and overall condition.
If you are comparing the options, see:
A boiler fault code by itself does not necessarily mean there is a gas leak.
However, if you smell gas or suspect a gas escape, stop troubleshooting the boiler.
Open doors and windows, avoid anything that could ignite the gas, and turn off the gas supply at the meter if you know how to do so safely.
In Great Britain, call the National Gas Emergency Service immediately on 0800 111 999.
Do not continue using an appliance you suspect may be unsafe.
Arrange professional diagnosis if:
For professional boiler fault diagnosis, visit:
If you’re in Cardiff and your Vokèra boiler is displaying a fault code, repeatedly locking out or has stopped providing heating or hot water, visit:
When booking, tell us:
A fault code identifies a problem or abnormal operating condition detected by the boiler. The exact meaning depends on the Vokèra model and generation.
No. Older and newer Vokèra boilers use different error-code systems, so always check the manual for your exact model.
On relevant older Vokèra boilers, A01 commonly relates to ignition failure or the boiler failing to detect a flame. The exact definition should be checked against the model manual.
On relevant newer Vokèra boilers, E010 is a flame-lockout fault.
On relevant newer Vokèra models, E040 indicates low heating-system water pressure requiring the system pressure to be checked and, where appropriate, refilled according to the boiler instructions.
A red light commonly indicates a fault or lockout, but its exact meaning depends on the Vokèra model and any accompanying code or LED pattern.
Use only the normal reset procedure stated in the user manual for your boiler. If the same fault returns, arrange diagnosis rather than continually resetting the appliance.
Many Vokèra sealed systems operate at around 1 to 1.5 bar when cold, but the correct pressure should always be checked in the manual for your particular model.
Let’s Heat can diagnose Vokèra boiler fault codes, ignition failures, pressure faults, recurring lockouts and heating or hot-water breakdowns.
You do not need to know which component has failed before booking. The exact boiler model and fault code are the most useful details to provide.
Vokèra uses different fault-code systems across different boiler ranges, so this guide has been checked against current and previous official Vokèra manuals and homeowner guidance.
Vokèra – Official Boiler Manuals & Literature
Vokèra – Official Homeowner Fault & Customer Care Guidance

Mo Alwadi is Renewable Manager at Let’s Heat and a Gas Safe registered engineer (registration no. 977042), with experience in domestic heating and air conditioning. He contributes technical guidance on boiler installation, boiler replacement, heating systems, air conditioning and home energy solutions, helping UK homeowners understand their options and make informed decisions.
View all posts by Mo Alwadi →


