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Vaillant Boiler F32 Fault Code - Flue Problem

The Vaillant fault code F32 boiler flue problem Q & A or require an engineer for an emergency boiler repair.


The Vaillant Boiler Fault Code F32 Error Common Q&A

Just below, we have a list of common questions relating to the F32 fault code on the Vaillant boiler.

Vaillant Boiler F32 Fault Code Error
  • I have a F32 fault code displayed on my Vaillant boiler, what does it mean?
  • What causes the F32 error code to be displayed?
  • Can I fix the F32 fault code myself by resetting the boiler?
  • How can my flue be blocked, and how will they clean it?
  • Do I need to replace the flue, or can it be fixed?
  • What electrical issues can cause a boiler to display the F32 fault code?
  • Can these parts be replaced, or will I need a new boiler?
  • How do I know if the PCB is broken?
  • Why would my PCB break on my boiler?
  • I don’t think my fan is working at all, is that causing the F32 boiler fault?
  • How can a heating engineer check if the fan on my boiler is working?
  • My fan is humming, will reducing the speed stop the noise?
  • How will they know if the bearings on the fan are broken?
  • How much will they charge me to replace the fan?

I have a F32 fault code displayed on my Vaillant boiler, what does it mean

According to Vaillant, the F32 fault code will be displayed when there is an air fault.

The fault is usually related to either the fan or the flue.

Once the issue has been diagnosed and fixed, the boiler will need to be reset to clear the F32 fault code.

What causes the F32 error code to be displayed

If the F32 fault code is displayed because of a flue issue, this is usually a blockage.

However, problems with the fan are a more common cause.

For instance, the rotation speed of the fan is potentially incorrect. This could be an incorrect speed setting, the fan has no power, or has power but isn’t running.

Although the fan can be sometimes at fault, there’s also a chance there could be a fault with the PCB.

The PCB needs to recognise the fan is running before it can fire up. If it doesn’t it will not ignite the boiler (and will potentially lockout).

Can I fix the F32 fault code myself by resetting the boiler

You shouldn’t attempt to fix issues with a gas appliance on a DIY basis. Get someone in that knows what they are doing; a Gas Safe engineer.

Resetting a boiler isn’t going to fix the fault.

Boilers lockout and display a fault code to highlight what the issue might be. Trying to run a boiler that has an internal fault could cause more damage, and be unsafe.

How can my flue be blocked, and how will they clean it

Although the F32 can relate to a blocked flue, it’s rarely as simple as this.

Boilers will try to determine the most relevant fault code possible, and a blocked flue is covered in the F32 error list.

But, unless the installation is completely incorrect, it’s actually very difficult for a flue to get blocked with debris.

If you have a horizontal flue (that comes out of the wall), the most likely blockage is the internal parts of the flue deteriorating.

For those with a vertical flue (coming out of the roof), a similar thing can occur.

But in this case, your flue should be fitted with some type of guard or cage. This stops debris dropping down into the flue.

If a guard isn’t fitted, there’s a good chance debris has made its way into the flue. The engineer will clear the blockage (or fit a new flue) and install a guard for the flue.

Do I need to replace the flue, or can it be fixed

It depends on the actual issue. If it’s a simple blockage and the condition of your flue is good, there’s no need for a replacement.

However, if the flue is old and the blockage means spending time taking the flue apart, it’s worth considering a replacement.

Not only is this going to last for years to come, but it can sometimes cost more in labour to clean and fix a flue, than just replace it.

For example, a standard horizontal flue for a Vaillant boiler is only around £85 with an elbow (parts only).

What electrical issues can cause a boiler to display the F32 fault code

When dealing with electrical components, its rare a simple visual check will allow a diagnosis for the problem.

So, it’s a process of elimination. The fault on your Vaillant boiler could be due to:

  • The plug on the fan has not be plugged in completely/correctly
  • The multi-plug on the PCB has not been plugged in correctly
  • Faulty hall sensor
  • Internal electronic issue, causing communication issues between the PCB and fan

And therefore, we always suggest calling a Gas Safe engineer.

The internal components (especially electrical ones) are extremely fragile and it’s easy to cause additional damage. Not to mention a DIY misdiagnosis could lead to an expensive repair bill, and the problem still occurring.

Can these parts be replaced, or will I need a new boiler

This depends on a few things. Namely, how expensive the parts are (assuming they are available).

One typical example of a boiler part that’s rarely worth replacing (on older boilers), is the PCB. This is the circuit board that communicates with other boiler parts.

In this case, if the circuit board is faulty, this could be what’s making the fan run at the wrong speed, and the boiler to lockout.

Due to the expense of a PCB, it’s usually a more cost-effective option to replace the boiler (but not always, so check with your engineer to discuss your options).

How do I know if the PCB is broken

It’s not as simple to diagnose a broken PCB as it is for something like say, a boiler that is leaking.

There are very few visual checks that point to a broken PCB.

A heating engineer can check that there is power to the PCB, and then power from the PCB to the fan.

If they can’t find power from the PCB to the fan, but there is power to the PCB, the fault lies there.

Why would my PCB break on my boiler

Old age is obviously a big concern when it comes to expensive boiler parts like the PCB.

However, a major killer of electrical components is moisture. In fact, that can be said of any electrical components.

Has your boiler been leaking? Or, have you noticed it losing pressure?

Even the smallest internal boiler leak can lead to moisture build-up on electrical components, and that’s when faults occur.

Newer boilers tend to have important electrical components fitted as sealed units. Older boilers; not so much.

I don’t think my fan is working at all, is that causing the F32 boiler fault

Any fan issue will cause the boiler to lockout and show the F32 boiler fault.

But, that doesn’t mean it’s the only problem.

As we mentioned above, your fan might not be working, but why? Is it the fan that’s broken?

Or, is it the fact that the boiler’s PCB is not communicating with the fan correctly. This would cause an “air fault”, but in this case, it’s the PCB and not the fan.

How can a heating engineer check if the fan on my boiler is working

First, they’ll check the terminals supplying the fan with electricity.

Next, they’ll check the windings on the motor. These can burn out and cause a fan to fail.

Likewise, the fans bearings can also cause issues. When bearings deteriorate, the problems with them snowball quickly. As they break up, they can cause the motor to jam completely.

My fan is humming, will reducing the speed stop the noise

It will certainly reduce it, but there’s a few things to consider here:

  • If the fan’s speed is too low, your boiler won’t be able to expel waste gases
  • What’s causing the noise in the first place?

Boilers will always lockout if current conditions are not within their operating tolerances(air pressure for instance).

In this case, flue gas levels will be too high, as the fan isn’t pushing them out of the flue.

The fan is designed to expel waste gases via the flue. By fixing one problem (humming noise), you’ll only be creating another (boiler locks out due to waste gases not being removed).

And, then there’s the point of what’s causing the issue?

For instance, if it’s the fan’s bearings making the noise, they are likely faulty. Turning down the fan speed might reduce the noise and prolong the bearing’s life, but only for a brief period.

How will they know if the bearings on the fan are broken

 

If the motor on the fan is jammed, there’s a good chance that’s the bearings.

However, you’ll be able to help them by explaining how the fault progressed over time.

Bearings on just about anything (not just boilers), will become noisy as they deteriorate.

They are designed to provide a pathway to low-resistance. And, that means minimal noise.

As they break down, they don’t do their job correctly. Resistance increases and that creates a whirring noise.

If the bearings in your fan are broken, it’s likely the whirring noise developed (and became more and more noisy) over the space of a few weeks.

How much will they charge me to replace the fan

No two boiler models are the same. So, that means prices for fan fitting will vary.

If we look at the Vaillant EcoTec, you should be expecting to pay around £100-200 for the fan itself.

If it’s a quick diagnostic, you should expect to pay £100-150 in total for labour. So, fitting a new fan could cost anything from £200, up to £350.

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 And Cures