An F62 signals that the gas valve is faulty, which can result from the valve being stuck or from a communication issue between the valve and the electronics. It should be fixed by a Gas Safe Engineer, and usually requires parts to be replaced.
The Vaillant F62 error code affects the EcoTec and EcoTec Pro models of Vaillant boiler.
What Does a Vaillant F62 Error Mean?
The F62 error signifies that the gas valve is faulty, and it will trigger a lockout.
When hot water or central heating is required, the boiler fires up and will need a supply of gas to heat the water. The gas valve controls the flow of gas into the boiler.
The valve should be open when hot water/heating is needed, but remain closed when the boiler is idle – if it remains open when the gas isn’t needed, then this can cause gas to leak into your home, which is very dangerous.
Therefore when the boiler detects a faulty gas valve, it triggers a lockout,= so that your boiler will not turn on, and displays an error code – in this case F62. When this error occurs, you should shut off your gas supply as a precaution and call a gas safe engineer to resolve the problem.
What Causes a Vaillant F62 Error?
Unlike other error codes, the F62 is connected to one direct cause: the gas valve is not opening and shutting correctly. This in itself can have a couple of different causes.
Stuck Gas Valve
Mechanical parts can become worn or clogged over time, and it is possible that the gas valve in your boiler has simply become stuck and is therefore unable to regulate the gas flow.
The F62 could be triggered as a result of the PCB sending signals for the valve to open and close at the wrong times, which would result in gas being allowed through the valve when it wasn’t needed and prevented from flowing when it was needed.
Intermittent Connection with PCB
If the gas valve cannot communicate consistently with the PCB, this means that it will not be receiving instructions on when to open and close, triggering the F62 error code.
How to Fix a Vaillant F62 Error
This problem can usually be fixed by freeing or replacing the stuck or damaged gas valve. The problem may also require the electronics to be repaired, and in some cases, a replacement PCB is required.
This can take a long time. It is unlikely that the plumber will have the correct parts to hand and so between finding the parts and the replacement itself, repairing this error code can take a whole day.
If faulty electronics are the cause of the problem then the engineer will also check for leaks within your boiler, as this is often the cause.
These leaks can usually be fixed, but water damaged electronics parts or PCB may also need replacing, and it’s worth weighing up the cost of these repairs against the cost of a new boiler.
Can You Fix a Vaillant F62 Error Yourself?
Legally, this kind of error must be dealt with by a Gas Safe Engineer; it is dangerous and potentially expensive to attempt to deal with a gas-related issue yourself. When you see the F62 error, you must call an engineer.
As with any gas-related issue, it is a good idea to shut off your gas supply until an engineer arrives to resolve the problem – even if you don’t smell gas.
Does an F62 Error Mean My Boiler is Broken?
No, this is not necessarily a fatal error. It could mean simply that your gas valve needs replacing or your electronics repairing. However, a new PCB may be needed and due to the expense of this part, it is often better to invest in a new boiler instead.
Is It Safe to Use the Boiler with an F62 Error Code Showing?
You will not be able to use the boiler while an F62 error code is showing, as it triggers a lockout due to the boiler being unsafe to use. Most boiler error codes trigger a lockout, especially when they are gas-related as these problems have the potential to be very dangerous.
Do I Need to Reset my Vaillant Boiler After An F62?
The boiler can be reset after the error has been fixed, but the reset function isn’t intended to be used as a fix-all.
At most, resetting the boiler before the error has been addressed will clear the error code briefly before the same error is detected, a lockout is once again triggered and an F62 error code displayed.
Once an engineer has addressed the issue, they will reset the boiler for you to get it up and running again.
How Much Will It Cost to Resolve An F62 Error?
To replace a gas valve can cost up to £300, and replacing a PCB is even more expensive – the part itself can cost up to £550. If the PCB is faulty and your boiler is more than a few years old, it is most likely more economical to invest in a new boiler rather than a replacement PCB.
I Can See Several Fault Codes. How Do I Know Which One is Correct?
Boilers can’t pinpoint the exact problem that has caused them to fail – the error codes are intended as a guide to diagnosing the problem rather than a diagnosis in themselves.
If you see a group of error codes displayed, they all likely relate to the same thing; for example, you might see an F62 displayed alongside an F28 or F29. The latter two both mean that the gas valve is adjusted incorrectly, while the F62 means the valve is faulty.
So although the exact issue hasn’t been identified, this combination of code tells an engineer that the fault very likely lies with the gas valve.