• 1. If a Gas Safe registered engineer inspects a gas appliance and identifies it as unsafe to use, they will follow this process.
    • Fix any faults present
    • You will be advised that the appliance must be repaired before it can be used again
    • If the engineer cannot repair the device immediately and he has the homeowners permission to do so, he will make the appliance safe by disconnecting the gas supply to the appliance or turning the gas supply to it off.
    If the engineer identifies the appliance as unsafe to use, he will attach a label indicating that the device is dangerous and should not be used. You will also be given a notice stating that the appliance is either:
    • Immediately Dangerous (ID)
      The appliance cannot be used, it is considered to be a danger to life and property. It should not be used again before repairs are carried out. With the owners permission, the appliance will be disconnected from the gas supply.
    • At Risk
      The appliance cannot be used, it is considered to be a danger to life and property. There are issues that without repair would endanger lives.
    If you refuse to allow an engineer to make the appliance safe, he will report the situation to the Gas Emergency Service Provider (ESP) who have legal powers to enter a property and make the appliance safe.
  • 2. If you have misplaced or lost your user manual, you can locate a replacement manual from this list of Vaillant boilers (please have your model number to hand).
  • We update the maintenance tips and troubleshooting guidance from time to time and aim to make it as helpful as possible. The purpose of the maintenance and troubleshooting section of this website is to provide you with general guidance. Please ensure you read and follow our instructions carefully and do not undertake the maintenance or troubleshooting unless you are aged 18 or over, are competent to do so and are confident that you can complete the maintenance. If in doubt do not attempt any actions and where an appliance is gas fuelled refer to a Gas Safe engineer for assistance.

    This website is not intended to be a substitute for professional advice and does not:
    - cover every reason that your product could fail;
    - cover all of the maintenance that can be undertaken for your product;
    - supersede any advice in your instruction manual or from your product manufacturer.

    Do not carry out any maintenance or use the troubleshooting guide if it puts you or anyone else in danger or if you believe it may cause damage to your, or another person’s property.