Viessmann Boiler Error Codes

Help! What does my Viessmann boiler error code mean?

Viessmann Boiler Error Codes


So your Viessmann boiler is displaying an error code? Don’t worry, fault codes don’t have to be scary, and even the most high quality boilers will experience faults as they age. Our guide can help answer any questions that you may have about Viessmann boiler error codes.


Viessmann Boiler Error Code F4 EE

Lets face it, the UK is not a hot country, so it’s common for the water in your boiler to freeze and cause a blockage in the condensate pipe. A displayed error code F4 EE means that this has happened and the boiler has locked out. Fixing this issue is something you can do yourself safely. To thaw the frozen condensate pipe, pour hot water (not boiling) over the blocked area. Watch this handy video for reference!


Viessmann Boiler Error Code F1 or A4

A displayed error code of F1 or A4 means that your boiler is experiencing a burner blockage. This problem is something you should never try to fix yourself, and always hire a Gas Safe engineer. Depending on the condition of your burner, it may need replacing rather than repairing. Click here to contact us to help.


Viessmann Boiler Error Code F5 or F6

If you’re seeing the error code F5 on your Viessmann boiler, it’s likely that there is a gas pressure problem. If this is the case, your boiler will lockout to ensure safety. This issue will need to be diagnosed and repaired by a Gas Safe engineer. Click here to contact us to help.


Viessmann Boiler Error Code B4 or FE

On a Viessmann boiler, the B4 error code will display if there is an internal fault that has been caused by a faulty printed circuit board. In some cases this printed circuit board can be fixed, but it usually needs to be replaced. Contact Synergi here.


Viessmann Boiler Error Code E4

This Viessmann boiler error code suggests that the flame signal in your boiler is either missing, or weak. This is dangerous, so your boiler will lock out to ensure your safety. A Gas Safe engineer must be contacted to fix this issue. Click here to contact us to help.


Viessmann Boiler Error Code F9

The F9 Viessmann boiler error code is a common one home owners see; it relates to the boiler’s fan. The fan ensures your boiler is safe, so when your boiler recognises the fan is faulty it will shut down. This problem can be fixed by a Gas Safe engineer who will diagnose and either repair the fan, or replace it. Click here to contact us to help.

Viessmann Boiler Error Code FC

FC = Fault Mode! There’s all sorts of reasons why this can happen to your Viessmann boiler, these being; 

  • A problem with the gas valve
  • An electronic fault 
  • Blocked vent system 
  • Faulty fan 

These issues could be dangerous. If you see the FC error code displayed on your boiler, call an emergency Gas Safe engineer who will be able to diagnose the problem and fix it. Click here to contact us to help.

Viessmann Boiler Error Code FR

An FR error code on your Viessmann Boiler will usually signal to fan faults. If this is the case, you may want to ask your engineer to check for signs of water damage caused by a leaky pump to prevent any further damage. Contact Synergi here.

When dealing with any kind of boiler, for any error code – if you smell gas immediately turn off the gas supply and contact a Gas Safe registered engineer.

If you’re seeing one of these error codes and it is one that can’t be safely solved yourself, we’re here to help as your local experts in everything boilers, plumbing and heating.

We are accredited boiler installers in Devon, Dorset and Somerset. If you are looking for some advice on what boiler is best for you or would like a quote for the installation or even a service & safety inspection on your existing boiler then give us a call on 01404 234363. We can guide you threw the different types of boilers, what money you could save and the entire installation process. There is a lot to consider when looking at having a new boiler fitted. Let us help to make life that little bit easier. Now available with a 10 year guarantee.

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