A Complete Guide to UK Boiler Warranties steffan@warmzilla.co.uk July 5, 2024

A Complete Guide to UK Boiler Warranties

A complete guide to uk boilers warranties from WarmZilla with a boiler and the WarmZilla logo
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    Buying a new boiler is a big purchase for anyone in the UK. The cost of a new boiler can vary widely but will be anywhere between £1,500 and £5,000.

    This range is simply because boilers come in many different sizes and fuel types. But we can collectively agree that whatever you end up paying, it’s a large purchase.

    So, what should you know about UK boiler warranties?

    Key Takeaways:

    • A boiler warranty is an agreement between the buyer and the manufacturer
    • A warranty and guarantee are very similar
    • You have consumer rights!
    • Boiler warranties last longer than legally required
    • Make sure to understand what is covered by the warranty
    • You will need to work on keeping the warranty valid
    • And always know what to look out for when reviewing a warranty

    Before going any further, let’s answer the most basic question.

    What Is A Boiler Warranty?

    A warranty is a written guarantee issued to the purchaser of an item by its manufacturer, promising to repair or replace it if necessary within a specific timeframe.

    It’s a financial safety net, providing peace of mind and reassurance, which is welcomed due to the amount of money invested into the appliance.

    Depending on your warranty, you could have access to someone coming out to repair or a total replacement it. Be aware that a warranty is different to a guarantee.

    Difference Between Boiler Warranty and Guarantee

    A guarantee is often considered the same as a warranty. But it isn’t.

    The main difference between a warranty and a guarantee is that the manufacturer issues the warranty to repair your boiler for a specific period after installation if you stick to the conditions of the written agreement.

    On the other hand, a guarantee is a promise or claim by the manufacturer or retail outlet that the product you bought is reliable and will perform. These guarantees can also include legal obligations to repair and replace your boiler (usually with a period attached to it).

    While confusing, the difference between the two comes down to the main reason for issuing a guarantee: your consumer rights.

    Consumer Rights With Boiler Warranties

    UK law protects citizens if the boiler they’ve bought is not working as promised or guaranteed.

    The Consumer Rights Act 2015 states that if a repair is unsuccessful after 30 days, the consumer is entitled to one of the following three options:

    • a free replacement,
    • for the company to repair the item (a boiler in our case),
    • a price reduction.

    Suppose your boiler’s fault occurred between the first 30 days and six months after purchase. The manufacturer cannot conclusively prove that their product was not fault-free. Therefore, the boiler manufacturer must legally accept that their product was delivered with a pre-existing defect.

    This means you are guaranteed to have your boiler replaced or fixed within the time period laid out in the Consumer Rights Act.

    Get a Boiler Service

    This leads us to our next point about reading the fine print in depth.

    Always Read And Understand The Warranty

    All new boilers come with a warranty. Understanding this agreement is the best way to avoid paying for repair work in the future.

    Also, if you don’t read the warranty agreement, you will not know what actions would make it null and void.

    There are various ways a boiler owner could void a warranty, so understanding your boiler’s warranty is the best way to avoid getting caught out.

    If you’re unsure about the boiler warranty wording, you can ask a salesperson or the company for clarification.

    Remember that the manufacturer’s warranty period will be stipulated in the written agreement between you and them.

    How Long Do New Boiler Warranties Last?

    All boilers in the UK are sold with a mandatory one-year guarantee that may be extended. However, most boiler manufacturers offer warranties and guarantees beyond the legal requirement.

    Selected boiler manufacturers and dealers offer warranties and guarantees with seven to 12 years of coverage.

    For the boiler brands that we sell on WarmZilla, the warranties are:

    Boiler BrandWarranty LengthWarmZilla workmanship Length
    Alpha10-year warranty on selected products12-month WarmZilla workmanship warranty
    Ideal8 to 10-year guarantee on selected products12-month WarmZilla workmanship warranty
    Vaillant10-year guarantee on selected products12-month WarmZilla workmanship warranty
    Viessmann10-year guarantee on selected products12-month WarmZilla workmanship warranty
    Worcester Bosch5, 7, and 10-year guarantees on selected products12-month WarmZilla workmanship warranty

    When Warmzilla installs your boiler, you will get a 12-month WarmZilla workmanship warranty. Our warranty includes parts and labour provided by the manufacturer.

    As mentioned, it’s best to read through your warranty carefully, as it will inform you what the manufacturers will cover after installing a new unit.

    What Does A Boiler Warranty Cover?

    Every boiler brand’s warranty or guarantee will offer different options. However, a warranty usually covers any interior components of your boiler if they break. This includes:

    • The pump
    • The heat exchanger
    • Flue passage in the boiler
    • The process control block (PCB)

    Again, this is a generalisation of what various brands could cover, so read your warranty. If there is an issue within the first year, most manufacturers will honour their warranty and repair it without hesitation, and a replacement boiler will be provided.

    Claims on your warranty will also differ depending on the manufacturer. But generally speaking, you will need:

    • To register your boiler for coverage (this will be different depending on the manufacturer)
    • A proof of purchase, which is typically a receipt that will show where and when the purchase was finalised
    • A photocopy of the warranty
    • To inform them of the current issue

    The last step, informing the manufacturer of the issue, is essential if the boiler maker is conducting a product recall, as it will speed up the process.

    Registering your boiler or having your Gas Safe register engineer register it for you is essential.

    After you’ve gathered your documents and written down the issue, you’ll need to submit your claim directly to the manufacturers:

    Boiler BrandContact Information
    AlphaContact Alpha in writing by email to info@alpha-heating.co.uk or submit by post to Unit 4a Vanguard Industrial Estate, Britannia Road, Chesterfield S40 2TZ
    IdealIdeal requires you to submit your claim via their Developer Connect platform or to join by emailing enquiries@idealdeveloperconnect.co.uk
    VaillantTo claim your warranty, register your appliance with myVAILLANT Web.
    ViessmannTo claim your warranty, call Viessmann After Sales Service on 01952 675060.
    Worcester BoschTo submit a claim, you can call them on 0330 123 9339 or send an enquiry via their website.

    However, can a manufacturer refuse to replace or repair your boiler?

    The simple answer is yes. We mentioned earlier that you need to understand the terms of the warranty agreement; otherwise, you could void the contract.

    How To Make Sure Your Warranty Remains Valid

    As some warranties are valid for up to 12 years, it can be challenging to keep the agreement going.

    However, understanding the contract is the best way to maintain any warranty agreement. But for those dedicated to keeping their warranties going, here are some tips to follow:

    Get A Gas Safe Register Engineer

    Almost every warranty agreement stipulates that the manufacturer requires the installation to be done by a Gas Safe registered engineer.

    Ensure you file away all documentation related to this installation, including the registered engineer’s credentials and any certification they provide.

    Register Your Boiler

    You should register your boiler with the manufacturer as soon as a Gas Safe engineer installs it. Most brands will give you a grace period to register the boiler via their own method, such as an activation code you use on their website, but again, this will differ between manufacturers.

    Generally, boiler brands allow you 30 days to register your boiler for its warranty. If you fail to complete this registration, your warranty will not be honoured.

    Regular Or Annual Services

    To ensure that your warranty is maintained, you need to schedule regular services. Most manufacturers require that an annual service be completed by a certified engineer.

    Get a Boiler Service

    While the manufacturers require this, it’s simply a good idea to service your boiler annually. A well-maintained boiler runs more efficiently, is cheaper to operate, and is less prone to expensive breakdowns.

    Only Use Original Parts

    While it can be tempting to select generic parts because they are less costly, some warranty agreements require that certified engineers use manufacturer-approved parts.

    Generally, manufacturer’s parts are more expensive than generic replacements. They also fit better and last longer. But if you don’t have the budget, review the warranty terms.

    Also, follow the manufacturer’s instructions on who can repair the boiler. Unauthorised repairs or modifications can void the warranty.

    Use As Instructed

    Always follow the instructions for using the boiler. Improper use can void the warranty. Make sure to check that you’ve not:

    • Set the pressure too high
    • Overfilled the tank
    • Set the temperature too high

    Keep All Documents

    Make sure that you keep all the documentation related to your boiler. This includes the:

    • Purchase receipt
    • Installation certificate
    • Servicing records
    • And all documents associated with the manufacturer.

    After all, if you claim from your warranty agreement, you will need proof that you’ve done everything by the book.

    Make Sure To Follow Water Quality Guidelines

    Some manufacturers specify certain water requirements for their boilers because the water quality entering your home can sometimes cause damage.

    Always ensure that your local water treatment complies with the manufacturer’s specifications to prevent damage and maintain the warranty.

    Your Gas Safe engineer should check the water quality being fed into your boiler and, with each annual service, flush and clean the system and add additives to prevent corrosion.

    Building Regulations

    You should also ensure your unit complies with local building regulations. Non-compliance with your local building code can affect your boiler’s warranty.

    While this documentation won’t be included in your boiler information, you can look for it online or at the local municipal office.

    Report Quickly

    File your claim as soon as possible. The longer you wait, the bigger your problem will get.

    And before we leave, let’s highlight what you need to look for when reviewing a warranty.

    Checklist For Reviewing A Boiler Warranty

    When reviewing a boiler’s warranty, there will be sections you will want to highlight. These areas include:

    Coverage Details

    Your warranty agreement will list which parts inside the boiler will be repaired or replaced. We mentioned these items in the article “What Does A Boiler Warranty Cover?

    What we need to add is that some manufacturers will cover labour costs and that certain components have their own warranty period. So now you know.


    It will be difficult for you to identify if there are any parts not covered by a warranty as you are not a certified Gas Safe engineer. Unless, of course, you are.

    Another area of exclusion is specific causes for damage. A warranty agreement often does not cover damage caused by corrosion or limescale.

    Warranty Extensions

    Always check if you can extend the warranty period for your boiler. Depending on the manufacturer, there are bound to be unique requirements to keep it in tip-top shape, but by following the instructions above for maintaining your warranty, you should be ready to go.

    If you have any other questions, please ask a consultant via the chat box in the bottom right-hand corner of the screen.

    Boiler out of Warranty?

    A boiler that needs frequent repairs after its warranty has ended is often a sign it’s time to upgrade. Don’t wait for a complete breakdown – explore your options for a new, reliable boiler that can save you money and hassle in the long run.

    Get a New Boiler