VAILLANT BOILER F62 FAULT CODE – FAULTY GAS VALVE

The Vaillant fault code F62 faulty gas valve Q & A or require an engineer for an emergency boiler repair.

The Vaillant Boiler Fault Code F62 Error Common Q & A

Just below, we have a list of common questions relating to the F62 fault code on the Vaillant boiler.

What does the F62 fault code mean on my Vaillant boiler?

What does the gas valve do on my boiler?

What could be the fault with the gas valve that’s causing the F62 fault code to be displayed?

How does the boiler know that the gas valve isn’t closing correctly?

Does the F62 fault code mean my boiler is dangerous?

Can I fit a new gas valve to fix the problem?

Is the reset function on my boiler designed to fix problems like the F62 fault code?

How will the engineer know if the F62 code is related to electronics, or the gas valve?

How much will it cost to fix the F62 fault on my Vaillant?

How long will it take an engineer to fix the F62 fault by fitting a gas valve?

What can cause an electronic failure, leading to a gas valve fault?

What can cause a leak, and how will that cause a F62 fault code to be displayed?

If multiple fault codes are being displayed, how do I know which one is causing the fault?

What does the F62 fault code mean on my Vaillant boiler

According to the Vaillant troubleshooting guide, the F62 fault code on your boiler relates to a faulty gas valve.

What does the gas valve do on my boiler

The gas valve communicates with your boiler’s circuit board (PCB).

When the circuit board recognises that the boiler needs to heat more water to keep up with demand from the thermostat, it needs gas to burn.

This signals the gas valve to open, providing more fuel, more energy, and more heat.

Once heat and gas supply is sufficient, the circuit board tells the gas valve to close.

What could be the fault with the gas valve that’s causing the F62 fault code to be displayed

This fault code is directly related to the gas valve not closing correctly.

So, your boiler is getting gas.

But, when the circuit board tells the gas valve to close, it’s not closing. Or, it’s not closing fully.

How does the boiler know that the gas valve isn’t closing correctly

The gas valve might not be completely stuck open. But, the boiler recognises that gas is passing by the valve, even when the valve is meant to be closed.

It can recognise this as there will be a flame still being detected even when the demand for gas isn’t there.

Alternatively, there is a fault with the electronics. For instance:

The gas valve (incorrectly) is being told to stay open

There’s an intermittent connection between the gas valve and PCB so it doesn’t always shut down when it should.

Does the F62 fault code mean my boiler is dangerous

The fail-safes in the boiler (such as it locking out), should prevent the unit from being dangerous.

However, if you do smell even the smallest hint of gas; turn off your gas, and turn off your boiler.

Call an engineer immediately. You shouldn’t be able to smell gas, and when you do, the unit suddenly becomes dangerous; it shouldn’t be turned on.

Bear in mind if you turn off your gas while you wait for the F62 fault to be fix, all other gas appliances will cease to work too (the hob, for instance).

Can I fit a new gas valve to fix the problem

Firstly, all gas appliances should be worked on by Gas Safe engineers. It’s unsafe to work on appliances if you don’t have accreditation.

When an engineer arrives, you can check their gas number here by scrolling down to the “check engineer” section.

Bear in mind, “business” and “engineer” checks are different. It’s unlikely their number will appear when searched via the “business” check.

Secondly, the issue could be just as easily an electronic fault, as it could be a gas valve fault.

Fitting a new gas valve without checking the electronics, could result in an expensive repair bill, and the F62 fault code still being present.

Is the reset function on my boiler designed to fix problems like the F62 fault code

No, this is not why boiler manufacturers incorporate a reset function.

A boiler will lockout and show a fault code (F62 in this case) because it’s unsafe.

Before resetting the boiler, the fault at hand needs to be fixed.

Leave the fixing and resetting of your boiler to somebody that is qualified.

How will the engineer know if the F62 code is related to electronics, or the gas valve

Before replacing parts, an engineer will fault find on your boiler. For example, they’ll use a multimeter to test connections.

Sometimes, simple visual checks are enough to determine whether electrical connections need attention.

How much will it cost to fix the F62 fault on my Vaillant

This depends on a few things.

Firstly, is the fault limited to the gas valve, or the electronics?

Sometimes these are the parts causing the problem, but it’s something else that has caused them to malfunction.

Secondly, the length of time spent fault finding and the type of boiler you have (which will dictate the cost of replacement parts) will also have a bearing on cost.

A typical gas valve replacement could cost up to £300 for a Vaillant boiler.

How long will it take an engineer to fix the F62 fault by fitting a gas valve

If you need to book time off work, expect to book a full day for a gas valve replacement.

The actual replacement could take just a couple of hours.

But, between fault finding, picking up replacement parts and fitting, the entire process could take a full day.

What can cause an electronic failure, leading to a gas valve fault

Older boilers are prone to electronic failures. Sometimes, this can be something as simple as old-age and general wear and tear.

Over time, connections (and parts) become worn, weak, and then break. Unfortunately, the only real fix here is to replace the offending parts.

But, when connections are damaged or burnt out, it’s likely there’s another cause; leaks in your boiler.

What can cause a leak, and how will that cause a F62 fault code to be displayed

In your boiler there are two places leaks tend to originate from:

The seals on the heating pump

A cracked heat exchanger

If they are leaking, they need fixing.

But, they will have already caused damaged in one of two ways:

They drip water directly onto electronic components, causing them to malfunction

The water from the leak is heated by internal boiler parts, and condensation settles on these electronic components, and causes them to malfunction

Newer boilers are not as prone to “condensation” based faults from leaks. That’s because the electronic components are usually sealed much more efficiently, than they are in older boilers.

However, if you have an older boiler, there’s a good chance condensation has caused the problem.

If multiple fault codes are being displayed, how do I know which one is causing the fault

Newer boilers can display multiple fault codes.

Because boilers don’t have the ability to pin-point the exact fault, sometimes there is some overlap between codes.

Depending on the different fault codes displayed, they might not actually narrow down the problem.

For instance, the F62 signals the gas valve won’t close.

But, according to Vaillant, the F61 fault code relates to an overall faulty gas valve.

Whereas F28 and F29 both cover “incorrect gas valve adjustment”.

They all sound very similar. And, they are.

Basically, a faulty or incorrect adjustment could lead to gas passing by (F28, F29, F61) which all could lead to the gas valve being stuck open; the F61.

If a combination of the above codes are displayed, there’s a good chance the gas valve is at fault.

This is what gas engineers get paid for. There job is to get an understanding of what could cause the problem, and then start fault finding.

Other Vaillant Fault Codes And Error

If your looking for the list of error codes relating to the Vaillant boiler then please read the article Vaillant Boiler Fault Codes.