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    Boiler Cleaning and Maintenance

    Boiler Cleaning and Maintenance

    Boiler cleaning and maintenance can be one of those things that you know you must get done but when you’ve got budget constraints, it can easily get pushed down the list. Problem is, if you do this it could well end up costing you far more than a straightforward clean and service.

    Why keep your boiler cleaned and maintained?

    Oil-fired and gas boilers should be serviced annually by an OFTEC registered engineer. It is important to keep your oil-fired boiler in good working order for a number of reasons including:

    • It ensures your boiler is fit for continued use and not releasing any illegal gases, such as carbon monoxide which is poisonous
    • It ensures there is less likelihood of your boiler breaking down, meaning you may well run out of hot water and have no heating – not what you want as we head into winter
    • It reduces the risk of major problems occurring at a later time, costing you significantly more for repairs
    • It ensures any warranty, which could be two to ten years, remains valid. A key requirement of most boiler warranties is to keep your boiler regularly serviced and maintained
    • It improves the lifespan of your boiler and keeps the running costs at a reasonable rate.

    This isn’t to say your boiler won’t ever experience any problems, it might. For example, a thermostat that is not performing sufficiently or the pilot light goes out regularly will usually mean replacing parts. However, the more you keep up with servicing and maintaining your boiler annually, the less likely any issues will occur.

    What’s involved in an annual boiler clean and maintenance?

    First, let’s just say, do not attempt to clean and maintain your boiler yourself. Apart from the fact that it will invalidate any warranty, an OFTEC registered engineer will issue you with a certificate on completion that advises your boiler has been serviced in accordance with current Building Regulations and OFTEC guidelines. This is important if you are insuring against any repairs or problems in the future and your insurance company may require a copy of this certificate.

    The cleaner your oil is burning, the more efficient your boiler will be. Termed ‘complete combustion’ by the engineers, it’s when your boiler is extracting the most energy from the oil. If any of the boiler’s parts – the fan (it fires the boiler and draws in the air from outside to keep the flame going), turbulators (they improve transferring heat to water) or baffles (they are used to control the flow of air and keep a healthy flame) – are dirty or carry a lot of soot, your boiler will not be working to its maximum capacity, known as ‘incomplete combustion’. Soot, which is a waste product from the fuel, can build up inside your boiler and cause more serious problems. Your OFTEC register engineer will inspect your boiler and carry out the following:

    • Inspect and check the combustion chamber rope seal
    • Remove and clean the boiler’s burner and fan
    • Descale and clean the baffles
    • Descale and clean the primary heat exchanger (this transfers the heat to water)
    • Remove, clean and put back the turbulators
    • Re-check the combustion levels following cleaning.


    The engineer will also check your oil tank and the pipe system that leads to your boiler, including:

    • Inspect and clean the condensate and condense trap (this is on the outside of the boiler, fitted on the condense pipe, and collects the condensation the boiler produces which can build up with sediment over time)
    • Inspect and test the fire valve
    • Clean the filter or replace it, if required
    • Visually inspect the oil tank and oil supply pipes for any damage, debris and deterioration, as well as noting general wear and tear
    • Pressure test the oil supply pipe, particularly where it travels underground to your boiler
    • Check and test the system pressure.


    Other maintenance checks your engineer will conduct include:

    • Check for any signs of bulges on a plastic tank or corrosion (rust) on a metal tank
    • Make sure there are no leakages or any physical damage, such as dents or cracks
    • Make sure there are no overgrown plants/vegetation affecting the tank, including any hanging branches from nearby trees. If there are, it will need cutting back
    • Inspect and check all pipe joints and for corroded seals around hatches and lids, making sure they are all secure
    • Test for any water that may have found its way into the tank. To do this, they have a long stick or garden cane that is coated in a ‘water finding paste’ and dip it into the tank all the way to the bottom. After a specific period, the stick is pulled back out and its colour is checked against an OFTEC chart, which will tell them if there is water present or not.


    You may be advised to have a Watchman or similar type of monitor fitted to your oil tank which will detect any sudden drops in the level of oil in the tank. This could happen if there is a leak in the tank or along the oil pipe system between the oil tank and the boiler.

    Once your engineer has completed a full and thorough clean and maintenance of your boiler and inspected your oil tank, as well as oil supply pipelines, they will issue you with an OFTEC CD/11 form which details all the work that they have done as part of the service. Keep this safe.

    BoilerJuice is the UK’s first heating oil comparison price platform with the aim of helping you find the best heating oil price in your area, quickly and easily. We work independently from heating oil companies and ensure our service is always totally impartial and provides consistently competitive prices, saving you money and time.

    Make sure you never run out of oil by signing up for a BoilerJuice Connected account. You will get a BoilerJuice Monitor complete with installation instructions (we are more than happy to get one of our professional engineers to install it for you). The monitor registers your oil levels, how much oil you use over a month or quarter, forecast your upcoming oil consumption and automatically place an oil order. You will receive an email confirming your order and be confident that we have taken advantage of the best oil prices on your behalf.

    Get your personalised home heating oil quote in just 30 seconds and get your BoilerJuice Connected account today.

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