A Vaillant boiler that is failing to power up is less than ideal, however modern devices are set to enter ‘lockout’ when there is a problem or a potential safety risk. Several underlying causes may result in your Vaillant boiler shutting down:

  • Poor gas supply
  • A leak in the boiler heating system
  • Low pressure
  • Overheating
  • Faulty electrical part
  • Old or worn-out components within the device
  • Blocked heat exchange
  • Insufficient intake from the flue
  • Ignition Failure

If any of the above occurs or a reset is required for another reason, the Vaillant boiler will display a fault code that should indicate the error which has caused a lockout.

What is a Boiler Lockout?

A boiler lockout occurs when your device shuts down due to an issue within the heating system. The initial solution is usually a reset. However, it is vital to consider that a reset will not solve an underlying problem with the boiler, and you will require assistance from a qualified Gas Safe engineer.

Where is My Vaillant Boiler Reset Button?

Your Vaillant boiler reset button is located on the boiler’s display, near where the fault code will appear. The reset button features a flame with a line through it – this is also the ignition button.

How Do I Reset My Vaillant Boiler?

  • Locate the boiler’s reset button
    The button will feature a flame, flashing light, or a cross and should be clearly labelled RESET in your instruction manual. Your boiler’s instruction manual will help you recognise this, as a detailed diagram of your specific model will be included. 
  • Press and hold the reset button
    Only press the reset button once as you may cause damage to the boiler’s control panel if this button is repeatedly pressed. This could then lead to additional repair costs.
  • Hold the reset button for 3 seconds
    Once you have held down the button for three seconds, you should be able to identify whether your boiler has been reset as changes will occur on the display. If a fault code remains in place following a reset, we recommend that you contact a Gas Safe Engineer for assistance to investigate the problem further. 
  • Further resets
    If the lockout persists or reoccurs, following three separate resets, then seek support from your approved Engineer. 

I have reset my Vaillant boiler, but it is failing to ignite…

There are many possible reasons why a boiler will fail to ignite, following a reset, which you may wish to check for before consulting a professional.

Thermostat Settings

Your thermostat is designed to control the boiler heating system, ensuring the property’s temperature is maintained to your preference. If the thermostat is located in a room that is at a higher temperature than the setting on your thermostat, then the central heating will not come on. Confirm the thermostat temperature and increase it; if that was the issue, then the boiler should begin to fire up. It is considered that the optimum home temperature is between 18-21°C.

Timer

In the event of a recent power cut, the timer on your boiler may have reset, which means that the boiler may not heat up when you are expecting it to or immediately following the reset. Should this occur, take a look through the instruction manual provided by the manufacturer for instructions on adjusting the timer settings.

Fuse Box

If there is no power to your boiler but other electronic devices within the property are operating as expected, check the fuse box as it may be a tripped switch that needs to be reset. 

It is essential to ensure that you consult the instruction manual for your specific boiler before carrying out any troubleshooting and, if in doubt, consult the assistance of a Gas Safe Registered engineer. Here at Rowlen we’re able to offer support via a quick phone call, or attend your residence in person to provide the best solution for your Vaillant boiler problem.