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Viessmann F2 Fault Code Causes & How To Fix It

Viessmann F2 error code – meaning and how to fix it


If your Viessmann boiler is having issues with its central heating system, there’s a chance that it is damaged or blocked and requires fixing. In this case, you are likely to see the Viessmann F2 fault code appear to tell you this, meaning you are probably going to need a Gas-Safe registered engineer to come and repair it.

You are probably wondering why your central heating system is faulty and what the causes are for this fault code, then don’t worry, we are here to help you. This guide will help you understand the ins and outs of your Viessmann boiler and what to do if this situation occurs.

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How to fix the Viessmann F2 fault code

When this fault code does appear, it is important and beneficial to address the issue as soon as possible. The best thing to do in this situation is to get a qualified Gas safe engineer to come out to your property and service your boiler to allow it to be back up to scratch and at its efficient best.

gas engineer

A fault code appearing on your boiler’s display could also mean that your boiler shuts down to prevent any further damage this issue could cause to the boiler or any potential danger that people could be put in with this. This will likely mean you will have a lack of hot water and heating, so getting it fixed will be extremely helpful in getting these back.

Fixing the boiler yourself can be done in certain situations, but is not always recommended as you always run the risk of further boiler damage or harming yourself due to lack of experience.

Should your boiler shut down, you will need to reset your boiler manually or get a qualified gas engineer to do so for you.

What a Viessmann F2 fault code means

If an F2 fault code shows up on your Viessmann boiler, it means that the burner in your boiler isn’t working properly and a lockout may occur. An ignition lockout is when your boiler has an emergency shutdown in the case of a fault or error in the heating system. This is achieved by preventing water from boiling so that you will be unable to use hot water when you need it.

There are a few reasons why this fault code and lockout take place, here we will go through them and explain what to do in each situation.

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Causes of F2 fault code

Flame loss in boiler

When there is a blockage in your central heating system or it has a fault, a cause of this could be boiler flame loss. This could be because the gas valve has a blockage of some kind preventing the flame from igniting.

To fix this, you should call a Gas Safe boiler engineer to come and look at your boiler, as the job of repairing this is best left to the experts. In some cases, the gas valve will be broken which will require a replacement gas valve so that your boiler flame can ignite again and your boiler works properly.

This may end up being costly as buying boiler parts is not always cheap, but if you have Viessmann boiler warranty, this replacement may be covered by that. Boiler warranty may end up being extremely helpful in many situations involving fault codes, so having a cover plan for your boiler should always be an option that is considered.

Frozen condensate pipe

Your condensate pipe is a component responsible for getting rid of acidic wastewater from your boiler and safely distributing it out of your home. It is a vital part of your boiler system and when not working effectively, can cause your boiler to shut down.

frozen condensate pipe

Most condensate pipes are located outside of your home, so during the Winter when the temperatures are the coldest, certain joints of the pipe where water collects can freeze and block the pipe system.

Fixing this is fairly easy and actually doesn’t necessarily require a gas engineer to come and sort it out. Firstly, heat up some water in the kettle so that it is hot/warm but not boiling, as boiling water could damage the pipe or burn you. Once it is at a hot enough temperature, slowly and carefully pour the water over the frozen condensate pipe to melt the ice and unblock the pipe system. After all of this, just reset your boiler and it should be back to its efficient best.

Alternatively, you can pour warm water into a water bottle and place it on or close to the condensate pipe to slowly thaw it out. This should be done if you aren’t confident enough to pour the water over the pipe or are worried about damaging it.

Blocked boiler flue

Your boiler flue pipe is attached to your system to let dangerous gases, such as carbon monoxide, out from your home, so keeping this intact is a good thing to monitor. It can sometimes get blocked by old debris, leaves or bird nests, especially if it doesn’t have a flue guard.

boiler flue

A blockage could mean that carbon monoxide isn’t properly filtered out of your home and your household is more at risk of a carbon monoxide leak, which is incredibly dangerous and can be fatal. This is why it is extremely important to make sure this blockage doesn’t continue for a long time along with it also affecting how well your boiler works.

If you do find that your flue is blocked, you will have to get a qualified gas engineer to come and clear it. They may also fit a flue guard to further prevent blocks in the future so your flue gases can be let out and you can have peace of mind about safety in your home.

Getting an inspection hatch for the flue can help enable technicians to assess the condition of the flue, check for blockages or damage, and perform necessary repairs or adjustments as needed.

Heating sludge blockage

Heating sludge occurs when dirt and rust are mixed with the water that passes through the boiler pipework, creating a dirty substance that can cause a blockage. This can also cause issues with your heat exchanger meaning your access to hot water and heating could potentially be limited.

Some of the signs that you have a heating sludge blockage are water leaking, CO2 being released and strange smells that could be coming from the sludge.

If this does occur, make to get a Gas Safe engineer to come and examine your heat exchanger as well as your pipes. They should be able to solve these issues for you and allow water and heat to flow through your system properly.

The method they would use would be a power flush, where chemicals are pumped through your pipes to clear all of the sludge and blockage. This service may be slightly more expensive than an ordinary service, but is well worth it when you consider the price you will end up paying on heating bills for an inefficient boiler.

Pump air lock

When your central heating pump has too much air in it, it can become stuck and locked meaning it won’t work as it usually should. You should look at the pressure reading on your boiler to see if it is within the recommended range that it should be, between 1 and 1.5 bars.

central heating pump

To remove trapped air in your pump, you will need a bleed screw that will allow the air to get out and unlock your heating pump. Then just reset your boiler and you’re good to go.

If your pump hasn’t been correctly installed, a boiler engineer should be able to fix this for you when you service your boiler, so your boiler can resume normal service.

Viessmann boiler service cost

boiler service

Taking the boiler service option on a lot of your Viessmann boiler issues is a good thing to get in the habit of. Although you will have to pay a fee for the engineer’s time and work, it likely won’t end up being more than a lot of the costly repairs you may have to make without it.

The average Viessmann boiler service is between £80 and £125, with the price depending on a number of different factors including model, type of boiler and what time of the year you get the service.

Viessmann boilers at a fixed price

If your Viessmann boiler is constantly having issues and consistently displaying fault codes, then these may be signs that you need a new replacement boiler. Getting a new boiler from Viessmann could end a lot of the problems that you are having and could mean that you actually end up paying less long-term.

Learn more about new boiler quotes online when looking for a new gas boiler by Viessmann.

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