Is your Vaillant boiler displaying the F76 fault code? Here we explain the most common causes and potential fixes.
Like with various boiler brands, Vaillant’s boilers have built-in fault codes that are designed to alert you to particular issues.
The Vaillant manual comes with an explanation of each error code and lists possible solutions.
Some fault codes can be solved by the homeowner, whereas others must be fixed by a qualified professional.
But what about Vaillant’s F76 fault code in particular?
Boiler old, unreliable and costing a fortune in repairs? Simply answer these questions, get your fixed price and you could get a new one installed as quick as tomorrow.
What Does F76 Mean?
If your boiler engine has overheated, it will trigger an F76 fault code. Your boiler will also shut off for safety.
This is thanks to the thermal fuse that is positioned above your boiler’s heat exchanger.
If the heat exchanger temperature is too high, the thermal fuse will turn off the boiler while an F76 error code will appear.
Causes of Overheating Boiler
There are, of course, a whole host of possible explanations for this specific fault. This is not an error to take lightly (not that any should).
This is a particularly serious fault and may mean your boiler needs to be replaced entirely, but more on that shortly.
Here are the potential causes of an overheating boiler engine:
Heat Exchanger has Trapped Air
If air becomes trapped inside your heat exchanger’s pipework, this can make it hard for your boiler to function properly. This can ultimately lead to your heat exchanger overheating.
To be more specific, the pipes of a heat exchanger are used to heat water and cool down waste gases before expelling them. If these pipes are disrupted by trapped air, it can cause problems.
Wiring Problems
If there is an issue with the wiring between the PCB and temperature sensors or between the PCB and pressure sensors or both, this can lead to an F76 error since the PCB could be receiving incorrect information.
Faulty Temperature Sensor
Similarly to a PCB wiring fault, an error with your boiler’s temperature sensor can result in the wrong data being processed, thus triggering an F76.
Physical Blockages
In a similar manner to trapped air, physical blockages can result in an F76 fault. However, this blockage could be present anywhere in your boiler and not just in the heat exchanger.
Can I Fix an F76 Fault DIY?
Unfortunately, an F76 fault cannot be fixed DIY. Sometimes, faults can be dealt with entirely DIY, while for others it will depend on what the actual cause is.
But an F76 fault is an example of a case where all possible explanations must be fixed by a Gas Safe Registered professional.
It is both unsafe and illegal for a DIYer to fix an F76 error code.
Do I Need to Have My Boiler Replaced?
You may need to have your boiler replaced entirely, depending on the nature of the issue that has led to an F76 fault.
You may simply choose to have your heat exchanger replaced. If a physical blockage in your boiler or/and heat exchanger is the problem and you decide to have your heat exchanger replaced, make sure that the heating engineer clears all blockages and completes a full servicing of your boiler.
It’s important to also be aware that replacing a heating exchanger does not come cheap so it would be worth considering a new boiler installation in this case.
If your boiler is old, it’s probably best to have it replaced as this will save you money in the long term and you may be looking at paying for a replacement in the next few years regardless.
If in doubt as to whether you should have your boiler replaced, it’s best to consult a professional or you can contact us to discuss your queries in more detail.
You may be interested in Gas Engineer Allen Hart explaining the most common boiler problems and how you can resolve them in the video below:
Cost of Hiring a Heating Engineer to Fix an F76
On average, the labour cost of hiring a Gas Safe engineer is £30 to £60 per hour.
However, this would depend on a range of factors including where you live.
Here is the average cost of fixing an F76 error code:
Replacing temperature sensor - £100 to £200.
Replacing heat exchanger - £640 to £1,080.
Other repairs - £100 to £400.
New boiler installation - £800 to £2,800.
The average cost of hiring a Gas Safe Register engineer is £30 to £60 per hour although this depends on factors like your location in the UK.
Here is the cost of specific fixes:
Topping up a boiler - £30 to £60.
Repairing a leak - £60 to £120.
Replacing a boiler component - £150 to 400.
Replace an entire boiler - £800 to £2,800.
Is your Vaillant boiler experiencing some of the brand's most common fault codes? We have many covered many Vaillant boiler error codes in the following guides:
Will my Warranty Cover Repairs or Replacement Work for an F76 Fault?
Vaillant’s boiler warranties only apply if a fix is required in relation to a defect caused by a manufacturing mistake.
If the error has resulted for any other reason, then your boiler warranty will not cover it.
Moreover, even if a manufacturing error has led to an F76 fault, you need to check that your boiler warranty has yet to expire.
The length of Vaillant’s boiler warranties varies depending on the appliance. In addition, specific Ts and Cs also cover these warranties.
To give some examples, a domestic Vaillant boiler warranty comes with these Ts and Cs:
Your boiler needs to be serviced once a year by a Gas Safe engineer.
It must have been fitted and commissioned within six months of despatch, again by a Gas Safe Register engineer.
So, unfortunately, in most cases, your Vaillant boiler warranty will not cover a repair or replacement job. This includes in the context of solving an F22 error.
Looking for a great deal on a new boiler?
If so, get your boiler replacement installed with Heatable. Here’s why:
Gas Safe installation within 24 hours.
Thousands of happy customers – an average score of 4.9 on Trustpilot (that’s better than the market leader).
Price match guarantee – if you find a cheaper quote, we will match (must be like for like).
Multiple payment options - interest-free available.
10-year guarantee.
Fixed price guarantee – no hidden costs.
Save your quote until later.
Use this clickable form to get a fixed price on the screen instantly.
Heat happy.