Boiler service costs: How much you should expect to pay

Close up of gas boiler being serviced
(Image credit: Getty Images)

Boiler service costs are often an afterthought once you have had a brand new boiler installed. However, if you want to keep your boiler in tip-top condition you will need to have it serviced at regular intervals. So how much will a boiler service cost and how often will you need to have it serviced?

Obviously if you are choosing a new boiler, it will be serviced when installed, but there are some factors which impact service costs going forward. A service will also reveal if you need any new parts to get it back running efficiently and effectively, ultimately keeping running costs down.  

Here we give you expert advice on boiler service costs, what a service should include and how often your boiler should be serviced.  

Boiler service costs: How much does it cost to service a gas boiler?  

The cost of a service depends on a number of factors but as general rule you shouldn’t be paying any more than £100 as Martyn Bridges, Director of Technical Services for Worcester Bosch, reveals: “A boiler service is typically between £70 and £100, however, some service providers offer service contracts which also cover breakdowns.”

If you are paying for a one-off boiler service you will typically have to pay more than if you are having regular services or are on a contract. As an example British Gas charges £99 for a one-off service and from £93 if you are tied into an annual service.

Independent local boiler engineers will often charge slightly less than a national chain so its best to check first. Mark Wilkins, technologies and training director at Vaillant suggests: “Your local heating engineer will best advise on the cost of a service as it varies depending on their offer. Some installers will service a product annually for a fixed fee, whilst others offer an insurance-style package covering the replacement of spares and labour where needed.” 

Duncan Craig of MAXGAS Boiler Services gives an insight into how much an independent typically costs: “The standard cost to perform a routine inspection and maintenance service on a wall-mounted boiler will typically cost between £60 to £90 including VAT depending on which company you use.”

He goes on to say that a service may reveal that further servicing may be needed. “Depending on age, manufacturers' service intervals or as a result of tests whilst doing an interim service that indicates more extensive servicing is required. 

"For example, Worcester Bosch boilers instructions ask the engineer to perform a test on the performance of the boilers fan to check how clean the heat exchanger is inside. If the fan test is below a certain reading on a gauge then a full strip down and clean is required and new gaskets and spark electrodes are often replaced at this time if required or thought sensible at the time. 

"These types of service vary in cost depending on exactly what parts are recommended and the labour time involved. But typically a strip down and clean service with new electrodes, burner door gasket etc., would cost between £150 to £225 depending on make and model of boiler." 

Man testing a wall boiler

Standard boiler services shouldn't cost more than £100, but if a more thorough service is needed expect to pay £150 plus. (Image credit: Getty Images)

How much does it cost to service an oil boiler? 

Oil boilers are typically more expensive to buy and run than a gas boiler but servicing costs are on a par with a gas boiler. You should expect to pay less than £100 for a service, but again – like gas boilers – different variables can affect how much you have to pay.  

What variables can impact the cost of a boiler service? 

Boilers come in all shapes, sizes and ages which can have an effect on the cost of a service, but this isn’t always the case as Mark Wilkins from Vaillant informs Homebuilding & Renovating: “The size and age of a domestic boiler is unlikely to impact the service cost. However, the type of boiler may vary the cost as sometimes additional work is needed like checking expansion vessels and pressure relief valves, also additional qualifications may be needed when working on unvented hot water cylinders.”

Location doesn't have any great bearing on the cost of a service, being relatively consistent across the country. However, the distance a gas engineer has to travel can put up the cost — so look for someone local.

Other variables that can affect the cost – though not directly related to service costs – are emergency or out of hours call outs and repairs and replacements. Both can add significantly to the cost of maintaining your boiler.  

There are other extras you may need to pay for, too. "If you have a hot water cylinder, you will also need this servicing annually, and it's often a good idea to have this done at the same time as servicing the boiler, if your engineer is suitably qualified. This will inevitably add to the cost of your annual boiler service," says Claire Lloyd, editor-in-chief of Homebuilding & Renovating.

"We may have other gas appliances, such as gas hobs and fires, which also need servicing annually. Again, it makes sense to have them serviced at the same time as your boiler, but this will all add to the final bill. British Gas currently charge £167 to undertake both a service on your boiler and a gas hob, for instance."

Is a boiler service worth it? 

A boiler needs to be maintained regularly to keep it working efficiently, so a boiler service is definitely worth it. Nobody wants their boiler breaking down in the middle of winter when it's needed most. Being without hot water and heat is a definite no and regular servicing will help keep a boiler running. 

But it’s not just the obvious lack of heating and hot water that can cause issues as Bridges from Worcester Bosch explains: “It is important to have your boiler serviced annually, not only to maintain its efficient operation but also to comply with the warranty terms and conditions. An annual service may also be needed to replace any seals, gaskets and perhaps electrodes that may have a requirement to be pro-actively replaced.”

The downsides to not getting your boiler serviced are obvious for the most part, but different manufacturers have different conditions as Bridges tells Homebuilding & Renovating. “You will need to check your boiler manufacturer's terms and conditions, but you may lose the warranty cover on your boiler if you don’t have it serviced annually. 

"You might also leave yourself more exposed to a boiler breakdown as the service would identify parts that could be showing signs of wear. Finally, the combustion settings need to be checked and if necessary reset to optimise efficiency.”

What does a full boiler service include? 

This may differ depending on what type of boiler you have and how old it is but an annual service will first start with a visual check where the engineer will look for any obvious signs of issues and make sure the pipework is up to scratch and there are no leaks.

The next step is to remove the boiler cover and check and clean components inside the boiler. 

Craig from MAXGAS Boiler Services describes what to expect from a service: “It should include removing the front cover, visual inspection of boiler and internal components, checking for leaks and signs of corrosion, electrical safety check and check polarity. 

"Also, if a condensing boiler, [this will involve a] check and clean of the condense trap if required and clean of the magnetic filter. If a sealed system e.g. a combi boiler or system boiler, then drop system pressure and check expansion vessel pressure, top up if required. Finally combustion checks using flue gas analyser and adjust gas valve as per manufacturers instructions to ensure the boiler is operating efficiently.”

If any components are not working as they should, the engineer may suggest replacement. It's often best to get the problem fixed quickly as the longer it is left the worse the problem may get. 

Man cleaning inside of a wall mounted boiler

A boiler service will include the cover being removed and components checked and cleaned (Image credit: Getty Images)

How often should a boiler be serviced? 

You will need to check the manufacturer's warranty and terms and conditions to make sure, but most boiler manufacturers expect the boiler to be serviced every 12 months to keep it in good working order. If it is not serviced regularly then the manufacturer is within their rights to void the warranty.

If you have boiler cover/insurance then this will typically state the same. If the boiler is not serviced regularly – typically 12 months – then the policy could be invalidated. So again make sure that you check the fine print of your policy to see how often you have to have it serviced.

If you are the landlord of a property a regular annual service is not a choice, but a legal requirement. And, the benefit of a regular service is that it will spot problems early and save you money in the long run.  

When should you service your boiler? 

It is worth noting that homeowners are not legally required to have their boiler serviced regularly. However, boilers typically come with a five to 10 year warranty, which means that if there is a genuine fault with the boiler during the warranty period, it will be fixed for free by the manufacturer. That said, for the warranty to remain effective, the boiler will need to be serviced every 12 months from the date of installation. 

But what is the best time of the year to get your boiler serviced? "Late spring, summer or early autumn are good times of the year to have your boiler serviced. Once 'heating season' begins, heating engineers tend to be busier with call-outs. And should your boiler need a new part or a serious fault is found, you don't want to be without heating for any longer than necessary in the colder months," says Claire Lloyd, editor-in-chief of Homebuilding & Renovating.

Who should service your boiler? 

A boiler needs to be serviced by a qualified person. “A boiler should be serviced each year by a Gas Safe-registered engineer," Wilkins from Vaillant explains. 

"Servicing your boiler will help to make sure it stays safe and uses fuel efficiently. There are clear requirements for servicing a boiler and in all instances, the manufacturer’s instructions should be followed for service and maintenance requirements."

Bear in mind that some local heating engineers specialise in particular brands. It's often a good idea to choose someone with expertise and experience with your brand of boiler.

How long do boiler services take? 

This will depend on what type of boiler is being serviced but expect a service to take around an hour. If, however, issues are found, then the service could inevitably take longer. Consult your engineer who will be able to give you more details. 

If you have a combi boiler a standard service should be slightly shorter and can take as little as 30 minutes. 

Steve Jenkins

Steve is Homebuilding & Renovating's DIY content editor, and has been a writer and editor for two decades. He is an avid DIYer with over 20 years of experience in transforming and renovating homes. He specialises in painting and decorating, but has strong all-round building skills, having previously worked in the industry for 10 years.