6 signs your heating system is crying out for a service, and why it’s best not to wait until you spot them before doing the essential maintenance
This is everything the pros want you to know
With an Arctic blast set to grip the UK, it's never been more important for your heating to be in good working order.
While you might not think about servicing your heating system until you see the signs your boiler is about to stop working, experts say regular maintenance is essential to ensure your heating works efficiently and safely, and to mitigate the risk of it failing when you need it the most.
Signs your heating system needs a service
The majority of UK homes use a mains gas central heating system to heat their homes and to provide hot water, and for it to work most effectively, and in the most cost-effective way, it needs to be in good working order. So it's a good idea to keep your eyes peeled for signs that all might not be well.
'There are several red flags that can indicate your heating system needs attention,' explains Rob Denman, Director of Gas Services at Gas Safe Register.
- 'Lazy yellow flames instead of crisp blue ones,
- dark or sooty marks around boilers or fires,
- or pilot lights that won’t stay on can all signal a problem.
- You might also notice weaker or uneven heat,
- unusual noises like banging or whistling,
- or higher-than-usual energy bills that suggest the system is working inefficiently.'
If you spot these signs, you should think about getting your heating system serviced pretty quickly to get it fighting fit again.
However, there are some warning signs that are indicative of a very dangerous problem that should be investigated by a professional immediately. 'If you smell gas, see scorching or black marks, notice a floppy yellow pilot light, or if anyone in the home has been feeling unwell with headaches, nausea or dizziness, it’s important to act quickly as these could indicate a more serious problem,' adds Rob.
Before joining Gas Safe Register in 2001, Rob was at British Gas where he started on a three-year apprenticeship, learning everything about gas from domestic to non-domestic and everything in between. Sitting on industry panels, Rob is passionate about the gas industry and making a positive impact. Along with his background and, having set up and run his own plumbing and heating business, he is well-placed to comment on all aspects of gas safety and the importance of using a registered gas engineer.
What are the benefits of getting your heating system serviced?
Having to fork out for a heating system service is a big reason so many people put off this maintenance task, but there are a whole host of benefits that make it a very worthwhile investment.
'The biggest benefit is safety,' says Earl Richards, Technical Manager at Cadent. 'A professional service undertaken by a Gas Safe Registered Engineer checks that your boiler and other gas appliances are burning fuel correctly and safely, reducing the risk of carbon monoxide leaks, which are colourless, odourless and potentially fatal.'
Beyond safety, Earl shared a number of other key benefits, including:
- Peace of mind that your home is safe
- Improved efficiency and lower energy bills
- Fewer breakdowns and unexpected repair costs
- Longer appliance lifespan
- Compliance with manufacturer warranties
- Early detection of faults before they become dangerous.
Even if it seems as if your heating is working fine, it's still worthwhile keeping on top of a regular maintenance schedule, as Rob Denman explains: 'Even if everything appears to be working fine, having it checked can help your home heat up quicker and stay warmer for longer, meaning you don’t need the heating on as much.'
Earl began his career as a gas engineer specialising in installation, service and repair and has worked for Cadent (formerly National Grid) since 2010.
What does a typical service include?
'A service will check that your system is running safely and that nothing is blocking ventilation or preventing appliances from burning correctly,' reveals Rob. 'For gas systems, that includes inspecting burners, ensuring chimneys or flues are clear, and looking for signs of poor combustion such as soot marks. The engineer may also check your radiators and pipework to ensure this is in good working order.'
Your engineer will also check for signs of leaks as well as the integrity of internal components and seals, cleaning or replacing parts if required.
'The exact checks - and how long they take - can vary between systems and manufacturers, but the key thing is ensuring that anyone working on a gas appliance is a Gas Safe registered engineer,' advises Rob.
A typical boiler service should take around 45-60 minutes, but if parts are required, this could increase.
FAQs
How often should you get your heating system serviced?
You might be tempted to wait until you spot signs of a potential breakdown before you get your heating services, but experts advise you do it on a regular basis.
'A boiler should be serviced annually to make sure it is running at its full potential,' says Martyn Bridges, Director of External Affairs at Worcester Bosch. 'It’s a good idea to schedule your boiler service during the summer when the boiler is largely inactive. Many people prefer to protect themselves from unexpected costs by taking out boiler cover-type insurance, which includes an annual service and breakdowns to ensure it is performing at its best.'
With over 40 years of experience in the heating industry, Martyn is a highly active, influential individual within heating and has held positions of high regard across the industry. This includes chairing the Technical Panel for the HHIC and being on the board for OFTEC, CIPHE and the Hot Water Association.
How much does a heating service cost?
'Costs vary, but most consumers can expect to pay between £70 and £125 for a standard boiler service,' says Earl. But while this is a solid benchmark for servicing a relatively new boiler that is in decent working order, costs could be higher depending on whether a fault is identified.
'The cost of repairing a boiler will naturally depend on the problem,' adds Martyn. 'Certain components can be quite inexpensive, while principal components like the PCB (printed circuit board) or heat exchanger can cost hundreds of pounds to fix. It’s always good to think about the long-term savings though, as a more efficient boiler means lower energy bills.
'You may even want to consider replacing your boiler completely; upgrading from a G-rated to an A-rated boiler can save homeowners up to £500 annually, depending on your property type.*'
*Figure correct as of July 2025, Energy Saving Trust.
Who should you get to service your heating system?
The experts I spoke to for this article all unanimously agreed that you should only ever use a Gas Safe Registered engineer to service their heating system. You can find an engineer and check their registration here.
As Rob Denman from the Gas Safe Register explained, this registration 'means they’re properly trained, assessed and certified as competent to work safely on gas in the UK, so households can be confident the work is being carried out correctly.'
Check out our guide for even more ways to keep your home warm in winter.
