Booking a regular boiler service can help keep your heating running safely and efficiently, while giving an engineer the opportunity to spot potential problems before they turn into inconvenient breakdowns. So, whether you've recently moved into a new home, had a boiler installed, or simply want to make sure your heating is ready for winter, here's what you need to know about boiler servicing.
A boiler service is a routine inspection and maintenance appointment carried out by a qualified heating engineer to check that your boiler is operating safely and working as it should. During the appointment, the engineer will examine the boiler, check it’s working, and carry out the maintenance recommended by the manufacturer. The work involved depends on the type of boiler you have, its age, and the manufacturer's servicing instructions.
For gas boilers, servicing must be carried out by an appropriately Gas Safe registered engineer. Oil boilers should be serviced by someone competent to work on oil-fired heating systems, with OFTEC registration providing a useful way to identify suitably trained technicians.
Keeping your home safe
Your boiler works hard throughout the colder months, providing heating and hot water when you need them. Like any piece of equipment that's used regularly, it can develop wear or faults over time. Having it serviced gives you an opportunity to identify problems early and make sure it's operating as safely and efficiently as possible.
Gas boilers that are faulty, incorrectly installed, or poorly maintained can present serious risks, including carbon monoxide poisoning. Carbon monoxide is particularly dangerous because you can't see, smell, or taste it, so it’s essential that you have properly maintained boiler, together with suitable carbon monoxide alarms, to help protect your household.
Reducing the risk of breakdowns
A boiler that's working today isn't guaranteed to keep working throughout the winter. Components can deteriorate, seals can wear, and small problems may develop without causing an obvious fault, and this is all more likely to happen during the winter when your boiler has to work its hardest. Regular servicing gives an engineer the chance to identify signs of trouble before they become more serious, although it can't guarantee that your boiler won't break down.
Helping your boiler run efficiently
A boiler that's operating correctly should use fuel more efficiently than one that's struggling with a fault or poorly adjusted components: during a service, the engineer can check whether the boiler is performing as expected and identify issues that may be affecting its operation. Although a service won't necessarily lead to a noticeable reduction in your energy bills, maintaining your heating system can help prevent avoidable inefficiencies.
Protecting your boiler warranty
Many boiler manufacturers require regular servicing as a condition of their warranty, so if you miss a scheduled service, you may find that certain warranty claims are affected, depending on the manufacturer's terms. It's worth checking your paperwork to see what maintenance is required and keeping a record of each completed service.
What happens during a boiler service?
A proper boiler service involves more than a quick look at the appliance. Your engineer should follow the manufacturer's instructions and carry out the checks appropriate to your boiler.
For a typical gas boiler, this may include:
- Visual inspection: Checking the boiler and accessible components for signs of corrosion, leaks, damage, or deterioration.
- Flue and ventilation checks: Making sure the flue arrangements are suitable and that the boiler has the ventilation it requires.
- Operating checks: Testing the boiler's operation and relevant safety devices to confirm that they're working correctly.
- Combustion analysis: Using specialist equipment, where required, to assess how efficiently and safely the boiler is burning gas.
- Internal inspection and cleaning: Examining and cleaning components where the manufacturer's instructions specify that this is necessary.
- System checks: Looking at relevant heating system conditions, such as pressure, where appropriate.
Once the service is complete, the engineer should explain any problems they've found and whether further maintenance or repairs are recommended. If they identify a fault ask whether it's something that needs immediate attention or whether further work can be arranged separately, and ask for a quote for how much they think it’ll cost.
How often should you service your boiler?
For most domestic boilers, an annual service is recommended, although you should always follow the manufacturer's instructions. This will you keep track of maintenance and provides an opportunity to identify problems before the next period of heavy use. If your boiler is older or has experienced repeated faults, an engineer may recommend additional checks.
When is the best time to book a boiler service?
Although you can have your boiler serviced at any time of year, late spring and summer can be particularly convenient as heating engineers may have more availability outside the busiest winter months, and arranging maintenance while you're using the heating less means any necessary repairs are less likely to cause major inconvenience.
If you've left it until autumn, don’t be tempted to wait until the following summer: book a service before the coldest weather arrives to avoid any nasty surprises.
Boiler servicing for landlords
If you're a landlord, you'll have additional responsibilities when it comes to gas safety. In the UK, landlords must arrange annual gas safety checks on relevant gas appliances and flues in their rented properties, carried out by an appropriately Gas Safe registered engineer.
It's important to understand that a gas safety check and a boiler service aren't necessarily the same thing: a gas safety check assesses whether the relevant gas appliances and flues are safe, while a boiler service involves maintenance according to the manufacturer's instructions. Some engineers can carry out both during the same appointment, so it's worth confirming what's included when booking.
As a landlord, you’ll also need to provide tenants with the required gas safety documentation within the applicable timescales.
Signs your boiler might need attention
Even if your boiler isn't due for its annual service, there are some warning signs that shouldn't be ignored.
Unusual noises
Boilers can make some noise during normal operation, but new banging, whistling, or gurgling sounds may indicate a problem. The cause could be related to circulation, trapped air, or another issue within the heating system. If the noise persists, it's worth asking a heating engineer to investigate.
Changes in heating or hot water
If your radiators aren't warming up properly, your hot water temperature keeps changing, or the boiler is taking longer than usual to heat your home, something may not be working as it should. These symptoms don't always mean the boiler itself is faulty, but they do suggest that the system needs attention.
Frequent pressure loss
Boiler pressure can vary during normal operation, but if you're repeatedly having to top it up, there may be a leak or another problem. Rather than continually repressurising the system, ask an engineer to investigate the cause.
Leaks or error codes
Visible leaks, repeated shutdowns, and persistent error codes are all reasons to contact a heating engineer. If your boiler has stopped working altogether, you may need a repair appointment rather than a routine service.
If you smell gas, suspect a gas leak, or believe an appliance is producing carbon monoxide, treat it as a safety issue and seek emergency assistance rather than waiting for a service.
Boiler service or boiler repair?
When you contact your boiler specialist it's worth explaining the symptoms when booking, as the type of appointment you need will depend on whether your boiler is working normally. A routine service is intended to inspect and maintain a functioning boiler, so if it's displaying a fault code, leaking, or failing to provide heating or hot water, the engineer may need to diagnose and repair the problem first.
Some repairs can be completed during a service appointment, but others might need replacement parts or additional time. If you're experiencing repeated problems, you may also want to discuss whether repairing the boiler is still the most practical option, particularly if it's approaching the end of its expected working life.
You may not think about it often, but your boiler is one of the hardest-working appliances in your home, particularly during the colder months. Regular servicing can help keep it operating safely, identify developing problems, and reduce the likelihood of an unexpected breakdown. If you can't remember when your boiler was last checked, now's a good time to arrange an appointment.
When booking a boiler service, make sure the engineer is qualified to work on your particular heating system. For gas boilers, they’ll need to be on the Gas Safe Register and qualified for the relevant type of appliance. You can ask to see their Gas Safe ID card and verify their registration online. It's also worth checking whether they're familiar with your boiler's make and model, particularly if it's an older appliance or has specialist servicing requirements.
TrustATrader can help you find vetted and reviewed boiler servicing specialists in your area, making it easier to compare local tradespeople and arrange the work you need. As well as providing customer ratings and reviews, our vetting team will check that the trader has the qualifications, insurance and certifications needed to do the work they’re offering, so you can find a gas-safe boiler engineer with complete peace of mind. For more tips and advice, or to share your experience, follow us on Facebook, Insta or Tiktok.