• 1. Combination (combi) boiler
    The benefits of using gas-fired combination boilers, is because they heat the water directly as it comes in from the mains, they do not require cold or hot water storage tanks. Because of this they are good solutions for compact homes.As with all modern boilers, combi boilers utilise heat exchangers to make use of the energy in the waste gasses to make the heating process more energy efficient.
    • They have an efficiency level of up to 98%
    • Do not require external storage tanks
    • Can power a shower without the need for a separate pump
    • They produce significantly less soot
    • They consume up to 30% less energy when compared to older heating installations
    • They require lower initial costs
    • They are quick to install
    • They can be expanded with other heating technologies
  • 2. System boiler
    Also known as 'sealed system boilers' they have an expansion vessel built into the boiler itself, so they do not require a header tank, only needing a hot water tank unlike regular boiler systems. This makes them ideal for homes with multiple bathrooms, as they can supply hot water to all the taps at the same time.
  • 3. Regular boiler
    Also called open vent, heat only or gravity-fed boilers, they provide central heating and hot water by the use of a hot water storage cylinder. This cylinder is usually installed in an airing cupboard with the cold water tank in the loft. A home with multiple bathrooms often suits an open vent boiler as they can provide a lot of hot water at the same time. If you have low water pressure and are replacing an old open vent boiler, a new open vent boiler should work well.
  • 4. If you have misplaced or lost your user manual, you can locate a replacement manual from this list of Heatrae Sadia 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.