Viessmann Boiler 14 Fault Code

The Viessmann fault code 14 relates to a multiple of issues and here we have Q & A or require an engineer for an emergency boiler repair.

The Viessmann Boiler Fault Code 14 Error Common Q & A

Just below, we have a list of common questions relating to the 14 fault code on the Viessmann Boiler.

What does fault code 14 mean on Viessmann boilers?
If my boiler shows the 14 fault code, is it dangerous?
Is there a quick-fix for the 14 fault code on Viessmann boilers?
What are the most likely reasons the 14 fault code is being displayed?
Are there any other problems that could lead to the 14 fault code being displayed on my Viessmann boiler?
How could the PCB on my Viessmann boiler be causing problems?
If the PCB needs replacing, how much is it likely to cost?
How can my Gas Safe engineer check the burner?
What could cause an ignition lead failure?
How will my boiler engineer know if the gas valve is causing the issue?
If I need a new gas valve, how much is it likely to cost?
What do blockages have to do with the 14 fault code on my Viessmann boiler?

What does fault code 14 mean on Viessmann boilers

If your display panel is showing the 14 fault code, it means the burner has switched to lockout mode. The printed circuit board (PCB) can’t detect a flame, and that means that it needs to lockout as a safety precaution.

The PCB is the heart of your boiler. It gives and receives a range of signals, to all electrical components. In this case, you’ve demanded for hot water or heating, meaning the burner needs to come on and establish a flame. The PCB expects to see a signal from the flame sensor to show that the flame is present, and that isn’t the case.

If my boiler shows the 14 fault code, is it dangerous

If your boiler doesn’t lockout, there’s a good chance it’s dangerous. If a flame isn’t present but the boiler is still running, this could mean that gas is letting-by into the burner. This is potentially dangerous.

By locking out, the boiler is no longer dangerous. However, if you suspect a problem, especially a gas leak, you should switch off your boiler and gas supply, then call a Gas Safe boiler repair company.

Is there a quick-fix for the 14 fault code on Viessmann boilers

There isn’t a quick-fix for fault code 14 on Viessmann boilers, mainly because the fault code isn’t 100% specific. Viessmann state that no flame signal leads to the 14 fault code being displayed, but there are no specifics as to what could be causing the problem.

For that reason, you need to call a Gas Safe registered engineer. They’ll be able to ensure the boiler isn’t dangerous before they start work on it. They’ll then determine what the problem is, fix it, and resetting the boiler will clear the fault code from the display panel on your appliance.

What are the most likely reasons the 14 fault code is being displayed

Your boiler engineer is going to start with the most obvious reason for the fault; the flame sensor. To determine whether a flame is present, your boiler relies on a flame sensor’s signal. If this flame sensor is faulty, it stands to reason that the PCB is going to think there isn’t a flame, even if there is.

So, the first point of call for your repair company, is to assess the state of the flame sensor. They’ll need to test the flame sensor for power using a multi-meter. Alongside the sensor, they’ll also want to check wiring and connections to the sensor and PCB.

Minor damage to wires can usually be repaired, and connections secured if necessary. However, if the flame sensor isn’t receiving power it may need to be replaced.

Are there any other problems that could lead to the 14 fault code being displayed on my Viessmann boiler

As we’ve already mentioned, the 14 fault code on Viessmann boilers doesn’t point to a specific component. Your engineer will need to fault-find any components and problems that can hinder flame signal, gas supply and ignition.

This means they’ll be looking to check the:

PCB for electrical damage and power
Burner isn’t blocked with debris
Ignition lead is in good condition
Gas valve isn’t sticking
Condensate pipe and flue for blockages

If the flame sensor isn’t the issue, there’s a good chance one of the above is what’s causing the problems with your Viessmann boiler.

How could the PCB on my Viessmann boiler be causing problems

The PCB controls almost every single component in your boiler. If this is malfunctioning, it’s going to throw up a whole host of problems. And, one of these problems could be that it’s not detecting the flame sensor’s signals correctly.

As an example, the flame in the burner could be strong. The flame sensor could be passing on this signal to the PCB, but the PCB isn’t receiving it. If this is the case, the PCB is going to determine that a flame isn’t present, even when it should be. As a safety precaution, it will shut down the burner and gas valve, and the boiler will lockout.

So, your engineer needs to test the PCB for power using a multi-meter, as well as any wires and connections to it. If the wires and connections are in good condition but the PCB still isn’t receiving power, it’s likely that the PCB needs to be replaced.

If the PCB needs replacing, how much is it likely to cost

The PCB is one of the most expensive parts in a boiler to replace, as it’s one of the most complex and important. A typical PCB replacement will be in the region of £400-500.

And like any boiler repair that are this expensive, you should consider asking your Gas Safe boiler repair company to assess the overall condition of your appliance. After all, you could spend £400 or more on repairs, only for other parts to fail a few months down the line.

How can my Gas Safe engineer check the burner

If the PCB is in good condition, another component worth checking is the burner and the jet. The burner can get blocked up with debris over years of use. And, that’s going to reduce its ability to efficiently create a stable flame.

When assessing the condition of the burner, your boiler engineer will also want to check the jet. These small jets supply a steady flow of gas to the burner, which in turn, creates that stable flame.

However, because these jets are so small they can easily get blocked, cutting the supply of gas. If the jet on your boiler is blocked, your engineer can clear the blockage, and reset your boiler to clear the 14 fault code from the display panel.

What could cause an ignition lead failure

Another possibility is that the boiler isn’t be able to create a flame in the first place, due to an ignition failure. Besides from old age, moisture from small boiler leaks could have hindered the ignition leads ability to operate.

So, after testing the ignition lead and determining whether this is the culprit, your boiler engineer will not just need to replace the lead, but also find and fix the leak. Typically, leaks can come from the boiler’s pump and/or heat exchanger.

How will my boiler engineer know if the gas valve is causing the issue

If a flame isn’t being created, the gas valve could be to blame. The gas valve controls the flow of fuel into the burner to ensure that a stable flame is created. And, like all moving mechanical parts, they wear over time.

But, instead of stopping working completely, gas valves tend to start sticking before they fail. If your valve is sticking partially closed, it’s not going to be supplying a steady flow of gas to the burner. In turn, that’s going to mean that a solid flame can’t be produced.

Your boiler repair company will start by testing the valve for power using a multi-meter. Assuming power is present, there’s a good chance that it’s giving and receiving the correct signals to and from the PCB.

Next, your boiler engineer will check if the valve is sticking. If it is, on some occasions, the valve can be freed.

If I need a new gas valve, how much is it likely to cost

If all else fails and a replacement gas valve is needed, you should expect to pay up to £300 including parts and labour. Assuming this is the only fault, after a reset, the fault 14 being shown on the display panel will be cleared.

What do blockages have to do with the 14 fault code on my Viessmann boiler

There are two main ways that your boiler vents harmful gases from your boiler to ensure that the appliance is safe.

The first, is the condensate pipe. This takes harmful flue gases from your boiler to the outside of your property. Typically, this is a small white pipe on the outside of your property.

If the condensate pipe freezes due to cold weather, that’s going to cause a blockage. The boiler is no longer safe to operate and that means a flame signal won’t be present. So, your boiler engineer is going to need to thaw out the pipe, to clear that blockage. They will then reset your boiler.

The second way your boiler vents harmful flue gases, is via the flue. This is a large white pipe that will look like it’s steaming when your boiler is on.

It’s not common for flue blockages to occur. However, if you have a vertical flue without a flue guard, debris can find its way in. Your engineer will need to clear the blockage and fit a flue guard to stop this problem from reoccurring.

24/7 call-out service