Vaillant Boiler Troubleshooting
Is your Vaillant boiler displaying an error fault code, failing to ignite properly or not producing any hot water? In this guide, we’ll discuss common Vaillant boiler issues, what error codes to look out for and what you can do yourself to fix the issues.
Common Vaillant boiler problems
Just like any make and model of boiler, Vaillant boilers will sometimes have problems.
Some of the most common Vaillant boiler problems include:
Do Vaillant boilers have warranty?
Yes, Vaillant boilers do come with a warranty; however, it does tend to vary depending on the model of Vaillant boiler you have.
The standard warranty of a Vaillant boiler is between 2-5 years, whereas some models have a warranty of 7-10 years provided they are installed by a certified Vaillant advanced installer. Some models may even be eligible for 10+ years of warranty if they are registered with Vaillant Advance scheme.
How do you reset a Vaillant boiler?
To reset a Vaillant boiler, you should:
- 1Find the reset button on the boiler's control panel. This is usually located on the front of the boiler, near the bottom.
- 2Press and hold the button down for around three seconds.
- 3Check the display on the boiler for any changes on the LED screen, such as the error code disappearing.
- 4Test the boiler by firing it up or turning on your hot water.
If the issue with your boiler persists, even after you have repeatedly reset it, you should contact one of our Gas Safe engineers to take a look at your boiler for you.
Why is my Vaillant boiler not firing up?
There are a number of reasons why your Vaillant boiler may not be firing up. Some issues may be simple to fix on your own, while others may require the assistance of a heating engineer.
Reasons your Vaillant boiler isn’t firing up can be caused by:
You can try to reset your boiler; however, if this doesn’t work, we highly recommend getting in touch with our team. Trying to fix the problem yourself is dangerous and you could end up making the problem much worse than it already is.
Vaillant boiler firing but there is no hot water
If your Vaillant boiler is firing up, but there is no hot water, there is likely to be a few different reasons as to why.
Some of the reasons and associated fault codes you may see are:
It's worth keeping your user manual handy so you can check your specific models' error codes.
How do you fix the pressure on a Vaillant boiler?
To fix the pressure on your Vaillant boiler, you will need to top-up the system by following the steps below:
- 1Turn off your boiler and let it cool down.
- 2Locate the filling loop under your boiler. The filling loop usually consists of two valves with a pipe connecting them.
- 3Open the filling loop valves by turning them to allow cold water to flow, keeping an eye on the pressure valve.
- 4
Wait for the pressure valve to display a normal range and then shut the valve off when the pressure reaches around 1.5 bars.
- 5
Restart the boiler and check for any leaks around the bottom of the boiler. Once you’ve allowed the boiler to heat-up and cool again, you should check the pressure and ensure it stays at a stable level.
How do you find the error codes on a Vaillant boiler?
Vaillant boilers will display the error codes on the display panel on the boiler itself. Depending on the model of your boiler, it may be visible at all times or be behind a flip-down panel.
The error codes will usually have an ‘F’ displayed in front of a number.
Vaillant boiler error codes
Depending on the model of your Vaillant boiler, there are a few different error codes you might see.
Some common Vaillant boiler error codes are:
