Common Vokera Boiler Faults [And What To Do Next]

Here we are going to cover the most common faults with Vokera boilers. Some faults have simple quick fixes but it always makes sense to call out a qualified Gas Safe engineer to assess the damage and advise on the best route forward.

Commong Vokera Boiler Faults

Vokera are not known for being particularly reliable–with numerous faults–but they are extremely popular. Why?

Big name heating merchants and boiler installers use them as their budget option, so they’ve found their way into thousands of owned and rented properties in the UK.

Just look at the incredibly short guarantees they offer. Many Vokera boilers only have a 2-year guarantee. In comparison, Worcester Bosch and Ideal offer 7-10 years on most of their range.

Understanding Vokera Boiler Faults

If the fault on your Vokera boiler has not been listed, please leave a comment and we will get back to you.

Alternatively, get help, and free boiler repair or installation quotes here.

And, if you’re thinking about a replacement boiler, we’d recommend Heatable. They fit Worcester boilers for a similar price as a local installer would charge for a Vokera. They come with a warranty of up to 10-years, and you can get your fixed price on screen in less that 90 seconds.

Vokera Boiler Fault 1: A03 Error Code Displayed

Let’s start with the A03 error code. This code is particularly common on the Vokera Compact boiler range.

The A03 code is showing the user that the problem with the fan. Quality fans will tend to outlast a lot of boilers. But, Vokera use lower end components in their products, so components like the fan are very likely to break before the boiler gives up the ghost.

Fixing a Faulty Fan

First, an engineer will need to diagnose what is wrong with the fan. In many cases, the whole fan unit does not need to be replaced.

A common cause of the A03 fan error is just worn bearings. Spares kits can be purchased from heating spares suppliers and they are easily replaced.

However, it’s worth asking the engineer to assess the situation of the fan, to check there’s not going to be issues further down the line.If there is, it would make sense to replace the whole fan whilst the boiler is apart.

If the fan is moving freely, it’s possibly a wiring issue. Using a multimeter, an engineer can check to see where the voltage drops.

Vokera Boiler Fault 2: Error Code 40, 41 or A04

The 40, 41 and A04 error codes are common on the Vokera Linea and the Vokera Compact. That said, this is possibly the most common issue with all brands of boilers; low pressure.

Boilers that lack pressure, or are losing pressure will not work correctly. Worse though, is the fact there could be a leak in the central heating system.

Fixing Vokera 40, 41 and A04 Error Codes

Topping up the boiler using the filling loop will likely get rid of the code, but it doesn’t solve the problem.

Identifying a leak is not as simple as it might seem. The leak can come from a whole number of different components such as the:

  1. Pump in the boiler.
  2. Radiators, towel rails and radiator valves.
  3. Auto air vent in the boiler.
  4. Expansion vessel.
  5. Stop taps and gate valves.

Do a quick check around all the above components and see if any are leaking. If they are, tightening them (extremely carefully) can sometimes fix the problem.

Once you’ve found the cause of the problem, get it fixed with a replacement as soon as possible.

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Vokera Boiler Fault 3: Water Isn’t Getting Hot

Either the water isn’t getting hot, or it only gets warm when you’re heating is on?

This boiler fault is most likely to relate to the diverter valve on the boiler. Unfortunately, the diverter valves on Vokera boilers (especially on the Flowmatic and Unica HE) are low quality and prone to failing.

The diverter valve in the boiler is crucial. A combination boiler heats hot water as and when you need it. When you turn on a tap, it switches its focus from your heating, to heating the water. Once the tap is switched off, it flicks back its focus to your heating.

It’s likely the diverter valve is stuck and not flicking to the hot water side. We’ve covered faulty diverter valves in more detail here.

Fixing a Faulty Diverter Valve

On many occasions, the whole diverter unit doesn’t have to be replaced, as the problem usually lies with the washers on the diaphragm. However, the cost of labour to disassemble and reassemble the boiler means that replacing the whole diverter valve is the best option.

The replacement diverter valves on Vokera boilers are usually much cheaper than other brands (it does depend on the exact) model, so £250 should usually cover the whole cost of the repair.

But, if your boiler is old and unreliable, it might be time to consider a replacement. You can get a guaranteed online price in less than 2-minutes here.

Vokera Boiler Fault 4: Fault Code 10 or A01

If you have a Vokera Linea, you’re going to see a boiler fault code of 10. On the Vokera Compact, the A01 error code means the same thing.

The boiler has recognised there is a fault with the boiler when it comes to ignite. This could be due to a few things. The most common cause is faulty ignition leads, or a gas valve not functioning correctly.

However, in many instances, the issue is with the PCB. And that’s not good news.

These units can cost up to £500 to replace. On an old boiler, it doesn’t make sense to invest this much cash, as it’s likely to develop more problems soon anyway. If it’s the PCB that needs replacing, it’s worth considering boiler replacement costs first.

Fixing the 10 and A01 Fault Code

A Gas Engineer will first need to figure out whether the issue lies with the ignition leads, gas valve, or PCB.

Once they determine the issue (usually by testing all circuits with their multimeter), they’ll be able to advise on the best route forward.

Vokera Boiler Fault 5: Fault Codes 92, 93 or 95 Displayed

Ironically, the 92, 93 and 95 fault codes that are displayed on Vokera Linea boilers relate to a problem most boilers will have at some stage; condensate blockages.

The blockage is either going to be in the trap that’s in your boiler, or the pipe that lets waste out of the property.

Fixing a Vokera 92, 93 or 95 Fault Code (Condensate Blockages)

If it’s cold, go outside and check that the pipe isn’t frozen. As bits of debris build up, moisture collects. As soon as it goes below freezing, all this moisture (and debris) freezes and blocks the pipe.

Use warm water to thaw the pipe work and try and remove any debris.

If it’s not cold somewhere along the pipe there is a blockage, this is just debris in the pipe.

Removing the pipe and flushing clean water through it will usually get rid of the blockage. If not, fitting a new pipe is an option (all plumbing merchants stock condensate pipes).


Most of the common Vokera boiler faults can be fixed quickly and inexpensively.

However, there are some faults (such as a broken PCB) that are just too expensive to fix. When a new boiler could save homeowners £200-300 per year on heating bills, and a fix could cost up to £500, sometimes the best option is a replacement. You can check the cost of a replacement on Heatable’s website. We recommend them above all, due to their low prices, guaranteed work, long warranties, and flexible financing options–even on bad credit.

If the fault on your Vokera boiler has not been mentioned, please leave a comment and we will get back to you.

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  1. Hi, my heating doesn’t come on for the upstairs radiators. Downstairs works fine, but when I switch on the upstairs setting, nothing happens. I have a Vokera 29a compact for both hot water and gas heating.

    1. Hi Guys
      My Vokera Compact 29A has recently started coming on during the night for 5secs and doing this every 30mins. The programmer is switched off so no demand & it is not going through ignition sequence just a short drone noise. I’ve checked manual and only things I can see relevant is
      1. Actuator anti-block function
      2. Pump anti-block function

      It’s doing my head in as weather is not cold enough for this to kick in. If you can advise to help I’d appreciate it

    2. Is it all the rads? If not, they could just need balancing.
      Would need to know more as it could be air in the system (try bleeding the rads with a bleed key), sludge in upstairs rads only, a faulty pump, or low pump pressure.

  2. Hello. My remote is showing fault code A84 and the heating is not turning off when this is pressed and has to be turned off at the main system. Can you advise me of what can be done to fix this.

  3. Hi there, hope you can help I have a Vokera Easi-heat plus 29C boiler 18 months old, it has started to lose pressure regularly. It was every few days originally, now its every few hours I keep topping up the system.
    I have checked my boiler/pipes and rads for leaks, none found, I have also cleaned out the condensate chamber and pipework as advised in my manual there was a slight blockage with a milky coloured water being emitted but still no joy, water is still dripping out of the condensate drain pipe. Any suggestions would be appreciated.
    Thank You.

    1. Hey Michael,

      There’s a quick guide on boilers losing pressure here: I’d go through and check all of that, or book in a repair engineer.

      Remember water can leak from almost anywhere (towel rails, rads, hidden pipework, rad valves, boiler filters, scale reducers etc).

      Water dripping out the condensate pipe isn’t an issue. It’s essential the exhaust for a boiler. When the boiler burns gas, it emits waste gas which condenses to water…that’s what’s dripping.


  4. Thanks for the info heatingforce, I understand about the issues with pipes, towel rails etc. but I’m sure this is not the problem as we have investigated thoroughly. When you say the condensate water isn’t a problem, I’m talking about a constant drip, drip, drip the whole time the boiler is running until no pressure is left in the boiler is this amount of exhausted water usual. If so then it looks like I’ll have to get a man who can in, after I’ve worked through the helpful link you sent me, thanks very much for your reply and your time.
    Best Regards,

  5. I have a Vokera Vision C combi.. 13 months old and had it’s service. Still under warranty. Had engineer out 2 weeks ago as after heating had been on and then I switch to hot water only…..then the radiators heat up even a few
    hours later.
    I had to go around house switching radiator thermostats to 0. Engineer replaced divertee valve…but it’s happening again
    Any idea if it could be another part involved too?
    Thank you!

    1. Hey Debbie,

      The diverter is usually the first shout. But yeah, there are other things that can cause the issue.

      Faulty Y-Plan/S-Plan/Zone valves for instance. Sometimes they can get stuck.


  6. MY boiler which is a vokera vision 30 combi has hot water working but will not heat the radiators. I have tried reseting it still does not work. A tap sign appears which only should appear when the hot water is in use this is showing all the time. The boiler is not showing any fault codes.

  7. Green light not coming on when responding to heating request. Does come on when responding to hot water request? Thoughts?

  8. I have a compact, heats water fine but no central heating. The heating did work for a bit when I moved in, but randomly, unable to set the thermostat and even when set to auto the heating doesn’t come on, which I believe it should in this cold weather!!! . Could it be a fault between the two bits of the thermostat system and not the boiler at all?

    1. Hey Harry,

      The Vokera E82 fault code relates to a distance/battery error, not allowing the radio frequency to work correctly.

      1. How can this be corrected, I have replaced batteries but the thermostat is still showing the same error. I have had no problems before it’s about 18 months old
        We have severe weather conditions at the moment could this be causing the problem (my boiler located in the attic my thermo located underneath in kitchen) At the moment my heating is on constantly I can’t switch it off via the wireless control pad?

  9. hi

    my boiler vokera vision 25c loses pressure after i fill it and close the valves the pressure drops steadily

    the only way it stops dropping is if i leave the filler valve open but then the overflow pipe runs outside

    i have checked the manual air release but this is ok

    what can be causing the pressure to drop ??

  10. Hello,
    I have a Vokera Unica 28HE. Recently the radiator temp display has started flashing. At higher temps this seems to make the boiler unstable and sometimes cause it to think it’s reached temp and turn off when it hasn’t reached temp. Unfortunately flashing temp isn’t an error code, any ideas?
    It seems to get better (temp not flashing) when I bump the control panel!

  11. Just installed a Vokera compact 29A boiler
    When powered up the venting sequence runs as it should when that is finished the hot water works fine but we are getting no central heating. Any ideas?

    1. Hi Gerard.

      So this is a new installation? I’d suggest calling the engineer back.

      Alternatively, I’d phone Vokera technical support: 0844 391 0999

      Hope that helps.

  12. Hi my boiler was working fine until I got up this morning had no pressure my partner fixed that now showing code AO1 on Vokera my boiler is due a gas safety check in Tuesday should I be worried

    1. Hi,

      A01 is an ignition fault on Vokera boilers. If you’ve lost pressure (likely a different cause), it’s likely you have a leak in your heating system.

      The leak could cause the A01 fault code by way of “dry fire”. I.e. the boiler recognises it’s not safe to ignite.

  13. Hi i have an error code E82 and the heating will not switch off I have decreased the temperature on the thermostat but the boiler is still firing up

    Desperate for assistance as Vokera enginers don’t work weekends !!!!

  14. Hi we have a vision c vokera boiler 2 years old. Only serviced 3 weeks ago. Showing code ACO. I can hear it trying to flash up then nothing?

  15. Hi, is it possible for a vokera vision 25s not to burn the gas correctly which leaves a rotten egg smell throughout the house. The house is new and I have had more problems with this house mainly with faulty plumbing throughout the house (very bad workmanship) I have had to call phoenix gas out 3 times but they couldn’t find any gas leaks thank goodness, so they said that it must be a faulty boiler causing the rotten smell, is there a way to check if this boiler is set up properly and is working properly. Please please help as people think that I am going mad but I know that there is something wrong with this boiler. Yours Richard.

    1. Has the boiler been sitting for a long period? Unlikely gas related, and a fault code would be shown if it was. More likely bacteria build-up on internal boiler parts.

  16. I have a Vokera Vision 30C.ehrnever I try to switch the boiler on I get a really loud gurgling noise followed by an A01 code. This is the 3rd time it’s happened in the last 6 months. What could be the cause?

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