Common Keston Boiler Problems & Repair Advice

Common Keston Boiler Problems & Repair Advice

Common Keston Boiler Problems & Repair Advice

Boilers don’t often cause much fuss in our homes as they are normally extremely reliable appliances, sometimes we can forget that they’re even there working hard to heat our homes. Should something go wrong though, the whole house soon knows about it and to help prevent panic kicking in, we’ve put together this handy guide.

Some boiler problems don’t even need the expertise of an engineer, and in this guide you’ll find out which you can tackle yourself, if you feel up to it. If in doubt though, always get in touch with an engineer, you can get a free boiler repair quote with our service.

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Who are Keston?

Almost 70 years of experience designing and manufacturing boilers has seen Keston grow far beyond their home in the Netherlands to share their passion for engineering with countries around the world. Find out more about this manufacturer and their full range of boilers here.

Top 5 Keston Boiler Problems

  1. Ignition failure

    If the boiler has failed to ignite five times then you’ll see the error code E01. The first thing to do is check that the gas supply is on, if it is then you’ll need to contact an engineer.

  2. No heat or hot water

    Your home can be without heating and hot water for a number of reasons, either broken diaphragms and airlocks, issues with the thermostat, low water levels or failure of motorised valves. Start off by checking if the boiler pressure or thermostat are the cause.

    Should your boiler need a new part, then you’ll need to get a Gas Safe registered engineer on the case. They’ll be able to thoroughly diagnose the problem and replace any broken parts.

  3. Radiators not heating up

    If your radiators aren’t heating up or are only heating up at the bottom then they may need to be bled. If you want to take on the task yourself then our guide to bleeding radiators can talk you through the process.

  4. Low pressure

    Checking a boiler’s pressure level is simple to do and can be done by simply taking a look at it’s built in pressure gauge, if it’s below 1 you may have an issue. It’s important to keep an eye on the boiler pressure because if it fails then it could lead to your central heating not functioning properly. Get to know more with our guide to low boiler pressure.

  5. Kettling

    If you’re hearing a noise that resembles a kettle boiling, the limescale or sludge may have built up on your boiler’s heat exchanger and this is called kettling. Having these deposits build up in your boiler can restrict the flow of water within the heat exchanger. The water can then overheat, causing it to steam and boil like in a kettle.

  6. Which Boiler Issues Need an Engineer?

    In the table below, we’ve listed the most common boiler problems and what might be causing them. Take a look to know if you’ll be needing an engineer or not.

    Need a boiler repair?



    Problem Possible Cause Do you need an engineer?
    No heat or hot water Broken diaphragms and airlocks, failure of motorised valves, issues with the thermostat or low water levels Yes
    Leaking and dripping Most common cause is a broken internal component but it will depend where the water is leaking from Yes
    Banging, whistling or gurgling noises A common cause is air in the system, alternatively it could be that the water pressure is too low or it’s kettling Yes
    Pilot light goes out Could be a broken thermocouple which is stopping the gas supply Yes
    Losing Pressure Could be a water leak in the system, the pressure relief valve needs replacing or due to recently bleeding radiators No, unless there’s a leak
    Frozen condensate pipe Your boiler will often display a fault code or warning notification Yes
    Thermostat issues Thermostat may be turned off or not set to the correct settings (time etc.) Consider replacing
    Kettling Limescale or sludge building up on your boiler’s heat exchanger Yes
    Radiators not getting hot Sludge or air build up in the system or an unequal distribution of heat You will need to bleed the radiators which doesn’t require an engineer unless you don’t feel like carrying out the task yourself.
    Boiler keeps switching itself off Could be low water pressure, a problem with the thermostat or a lack of water flow due to a closed valve, air or the pump not circulating the water in the system properly Yes

    Keston Error Codes

    When there’s something wrong with you Keston boiler, you’ll see an error symbol appear on the screen, usually a capital letter followed by a number. If you’re seeing an error code then check our list of Keston error codes to find out what it means.

    Should You Replace Your Keston Boiler Instead?

    If your Keston boiler has been heating your home for a number of years, then you might be thinking about getting a new one as you could be saving up to £305* a year in a detached home. Take a look at the table below to see how much you could be saving depending on your current boiler rating and property.

    House Type G (<70%) F (70-74%) E (74-78%) D (78-82%)
    Semi-Detached £200 £140 £120 £120
    Detached £305 £210 £180 £180
    Detached Bungalow £155 £105 £90 £90
    Mid terrace house £175 £120 £105 £105
    Mid terrace house £95 £65 £55 £55

    Who Should You Choose to Replace a Keston Boiler?

    Deciding who to replace your boiler can be a big decision as you want to make sure that you’re getting the best deal possible. The choice here comes down to a local engineer or national company.

    Local engineers can come with very competitive rates and if you like a personal service then you’re likely to talk to the same person throughout. It’s always a good idea to get a quote from more than 1 engineer to make sure you’re getting the best deal, we recommend getting up to 3.

    Branded manufacturers may be slightly more on the expensive side, you’ll have big brand protection which is a huge bonus and they can offer extra service such as ongoing boiler cover.

    Boiler Insurance and Ongoing Cover

    If your boiler warranty has expired, then boiler insurance is a possible option. You can take out insurance with your energy supplier but you’re absolutely no obligation to do so. When comparing insurance, the best ones will include an annual service and safety inspection, so keep an eye out for them.

    Keston Boiler Warranty

    Keston boiler warranties vary depending on the model you purchase but since 1st January 2018, the standard warranty of their Combi and System boilers has been increased to 5 years. We’ve put together a complete guide to Keston warranties so that you know exactly what to expect.

    Hire a Gas Safe engineer to carry out an annual service of your Keston boiler to keep the warranty valid and make sure the unit is running safely and efficiently.

    Send us an enquiry today to receive free quotes for a new boiler and find trusted engineers near you with our free service.

    *According to the latest figures from the Energy Saving Trust

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