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Do you have a Vokera Boiler Error Code problem?

Is your Vokera boiler giving you trouble? If it’s not working as it should, check the boiler to see if it’s displaying an error code. This should let you know what the problem is and potentially what you need to do about it. 

Of course, if you’re not a Gas Safe engineer, you aren’t permitted to take the boiler’s case off, unscrew any of its panels or remove any parts. If you need to do any of those things, you’ll need a professional touch. 

In addition to using the list below to diagnose your Vokera boiler error, you can speak to a qualified professional through a 15-minute video call with to help you identify your fault. 

If you don’t see your boiler model below, or you see it but simply don’t know what to do with the knowledge that it’s your hot water negative thermistor coefficient sensor that’s playing up, don’t despair. You can book a 15-minute video call with an experienced professional through Herofix, to help you diagnose the fault.

Vokera boilers we have covered in this error code list:

Vokera Boiler Error Codes

Error CodeFault ImageSystem Behaviour
_CLN/ACall for service
A01Vokera Error PictureIgnition failure flame not sensed – internal fault
A02BellLimit thermostat fault
A03BellFan fault
A04BellInsufficient system water pressure
A06BellDomestic how water (DHW) thermistor fault
A07BellPrimary flow thermistor fault – temperature of water is too high.
A08BellReturn thermistor fault – water temperature too high.
A09BellFlue thermistor or flue thermistor counter fault.
A11BellFalse flame
A77BellLow-temperature thermostat fault
ACOBellService Operation
N/AFlameFlame on
Error CodeSystem Behaviour
PPreheating function active
P BlinkingPreheating function running
1Failure to ignite
3Problem with fan/flue
4Insufficient water pressure
5Reset as described for code 01
6Hot water thermistor open circuit
7Primary thermistor open circuit

Vokera Mynute Boiler Error Codes

Error CodeSystem Behaviour
AL10, AL20, AL21, AL26, AL28, AL34Try resetting the boiler, if the fault reoccurs you need to contact a heating engineer.
AL40Check the system’s pressure and refill if necessary. Reset the boiler, if the fault reoccurs then you need to contact a heating engineer.
AL41Check system pressure – refill if necessary. If fault reoccurs, contact a heating engineer.
AL52, AL55, AL60, AL71,AL73, AL74, AL79Contact a heating engineer.
AL74, AL79Reset the boiler. If the fault reoccurs, contact a heating engineer.

Evolve Combi Evolve System Error Codes

Error CodeSystem Behaviour
E10Flame lockout
E011Extraneous flame
EO20Limit thermostat
E030Fan Fault
E040Water transducer – check system water pressure
E041Water transducer – check system water pressure
E042Water transducer fault
E060Domestic hot water probe fault
4070Fault flow sensor over temperature – flow sensor flow/return line probe differential alarm
E077Main zone water thermostat
E080Error with return line probe – over temperature outlet or differential alarm
E090Flue gases over temperature probe
E091Clean primary heat exchanger
Water pressure low
Water pressure high
Boiler board communication lost
BUS 485 communication lost
E021, E022, E023, E024, E067. E088, E097Iono alarm
E085, E094, E095Combustion fault/high CO
E058Main voltage error
E065Current modulation alarm
E086Obstruction fumes alarm

Vokera Boiler Red Light On

Vokera boilers without a digital display won’t have an error code to let you know what’s wrong. However, they do have red and green lights that will either remain on constantly or begin flashing, depending on the situation. Read our guide to the Vokera boiler red light on Boiler Guide to get your boiler back up and running.

Vokera Red Light Causes

If your Vokera boiler has a constant green light and no red light, there’s nothing to worry about – your boiler will provide heating and hot water as normal. However, if you see a red light on its own or alongside the green light, then there’s a potential fault with the boiler.

Below, we’ve listed the issues that can cause various sequences of light that you’re likely to see on your Vokera boiler when it’s broken.

Red Light On and Green Light Off

A constant red light on your Vokera boiler means that the unit has gone into lockout for safety reasons. Some of the possible faults behind this include:

  • The boiler is overheating
  • The pump isn’t circulating hot water around the central heating system or to the taps when required
  • Potentially harmful flue gases aren’t being expelled due to an issue with the fan

Red and Green Lights On

If you’re seeing both red and green lights on your Vokera boiler at the same time, whether they’re remaining on or flashing, your boiler could have one of the following problems:

  • It has been left in service mode after a recent boiler service
  • Incorrect water pressure (either too low or too high)
  • Heating temperature sensors are faulty

Flashing Green Light

A constant green light on your Vokera boiler is a sign that the flame within the boiler is working. That’s what you want to see. Should the green light start flashing, that’s when there could be an issue to worry about, including a faulty hot water sensor of the boiler being in standby. 

How to Reset a Vokera Boiler

A simple reset could be enough to stop your Vokera boiler from flashing red and get the unit working to heat your home and hot water again.

To reset your Vokera boiler, move the mode selector switch to the ‘OFF/RESET’ position and then move it back to either ‘hot water only’ or ‘heating and hot water’. Should this reboot get your boiler working again then you’ll know because there will be a constant green light. If not, you should hire a Gas Safe engineer to come out and look over your boiler.

How to Reset a Vokera Boiler

Vokera boilers with a digital display will show an error code alongside the red light, which will help to get to the root cause faster than the boilers without a display.

A common Vokera boiler error code is A01. This means that the boiler has failed to ignite. There are many reasons why a boiler might fail to ignite, from no gas supply to a faulty ignition lead or PDB board. You’ll need a Gas Safe engineer to diagnose and repair the A01 fault, as you should never carry out any work on your gas boiler yourself.

If you’re in any doubt, it’s important to consult a professional heating engineer. You can book at 15-minute video call at