Your boiler works. The radiators get warm. The shower does too. So why think about maintenance? That's exactly why servicing is so easy to put off.
But regular boiler maintenance matters. Older central heating boilers often benefit from an annual service, while some modern boilers only need servicing every two years. Always follow the manufacturer's recommendations. And there are a few things you can safely check yourself, such as the water pressure and bleeding your radiators. For technical maintenance, you'll need a CO-certified heating engineer.
Boiler maintenance at a glance
How often? Older boilers usually once a year. Modern boilers may only need servicing every two years, depending on the manufacturer's instructions.
Best time? Before the heating season, preferably in August or September.
What can you do yourself? Check the water pressure, refill the heating system, bleed radiators and remove dust.
When do you need an engineer? For technical servicing, combustion checks, flue inspections and repairs.
What does it cost? Boiler maintenance through Zoofy starts from €129 including VAT.
Why bother? To reduce the risk of breakdowns, excessive wear and safety issues.
Jump to:
How often should you service your boiler?
Not every central heating boiler needs servicing at the same interval. It depends on the age, brand, model and how heavily the boiler is used.
As a general guideline, older boilers should be serviced annually. For many modern boilers, servicing every two years may be sufficient.
However, the manufacturer's maintenance schedule always takes priority. Some boilers require yearly servicing, while others are designed for longer intervals.
How often should different boilers be serviced?
Older boilers: Annual maintenance is generally recommended.
Modern boilers: Often every two years, provided the manufacturer allows it.
Heavily used boilers: Ask your heating engineer whether more frequent servicing is sensible.
Rarely used boilers: Periodic maintenance is still necessary. Less use doesn't automatically mean less maintenance.
Boilers with recurring problems: Have the problem checked rather than waiting for the next scheduled service.
Not sure how old your boiler is or when it was last serviced? Check the appliance information plate, maintenance sticker or previous service reports.
Can't find anything? It's worth having an engineer assess whether servicing is overdue.
When is the best time for boiler maintenance?
The first freezing morning of the year is an excellent time to discover that your heating doesn't work.
Just not a particularly convenient one.
That's why it's sensible to schedule boiler maintenance before the heating season begins. August and September are practical months. You probably don't need the heating much yet, and there's time to replace worn parts before winter.
Why schedule maintenance before winter?
You can identify problems before you rely on your heating every day.
Worn components can be replaced in good time.
You reduce the chance of discovering a problem during a cold spell.
You start the heating season with a checked system.
If your manufacturer's service schedule says your boiler needs maintenance in March or June, there's no reason to wait until September. Following the recommended service interval is more important than choosing the perfect month.
What boiler maintenance can you do yourself?
You don't need an engineer for every little check. There are several things you can safely do to help keep your central heating system working properly.
Most take just a few minutes.
Which, strangely enough, doesn't stop people putting them off for months.
1. Check the boiler's water pressure
Take a look at your central heating system's water pressure several times a year.
For many systems, the normal pressure when cold is around 1.5 to 2 bar. Always check your boiler manual, as the correct pressure can vary.
If the pressure is too low, the system may need refilling.
But if you need to top it up every few weeks, something else may be wrong. A leak or faulty expansion vessel, for example.
2. Refill your central heating system when necessary
Refilling the heating system is a normal user task for many boilers, provided you follow the manufacturer's instructions.
Check the recommended water pressure in your boiler manual.
Switch off the heating and allow the system to cool sufficiently.
Connect the filling hose according to the instructions for your installation.
Avoid introducing unnecessary air into the system.
Fill slowly until you reach the recommended pressure.
Close the valves and disconnect the hose as instructed.
Check the system for leaks and make sure it is functioning normally.
Not confident about your boiler's filling procedure? Get someone to help. Connections and procedures can differ between systems.
3. Bleed your radiators
Does a radiator stay cold at the top while the bottom gets warm? Or do you hear bubbling noises?
There may be air trapped in the heating system.
You can usually bleed radiators yourself using a radiator key.
Switch off the heating and let the radiators cool.
Follow the instructions for your heating system.
Place a cloth and small container under the bleed valve.
Carefully open the valve.
Let the air escape and close the valve when water starts to appear.
Check the water pressure afterwards.
If air keeps returning to the system, bleeding the radiators probably isn't solving the underlying problem.
4. Keep radiators and convectors clean
Dust and dirt can reduce how effectively radiators and convectors release heat into a room.
Regular cleaning helps keep the system working efficiently.
Pay particular attention to the spaces between radiator panels and convectors where air needs to circulate.
5. Check the thermostat and heating settings
Is your home not getting warm enough? Before assuming the boiler is faulty, check the thermostat.
Make sure it's working correctly, replace batteries if necessary and check that radiator valves are open.
You can also check whether the central heating flow temperature can be lowered to save energy. Depending on your home, a setting of 50 or 60 degrees Celsius may still provide enough warmth.
Don't simply lower the domestic hot water temperature. Safe hot water settings are important to prevent Legionella risks.
If you're unsure about the settings, ask your heating engineer to go through them during the next service.
What boiler maintenance should you leave to a professional?
Checking the water pressure is one thing.
Opening the boiler to clean the burner yourself is another.
And that second one really isn't a Sunday afternoon project.
In the Netherlands, technical work on gas combustion appliances must be carried out by a CO-certified company.
Leave the following tasks to a certified heating engineer:
Cleaning the burner and heat exchanger.
Checking and adjusting combustion settings.
Inspecting technical gas connections.
Checking the flue and combustion air supply.
Replacing internal boiler components.
Testing safety systems.
Diagnosing and repairing internal boiler faults.
A boiler may appear to be working normally even when there is a problem with combustion or the flue system.
That's not something you can reliably judge by looking at the outside.
Book professional boiler maintenance →
When does your boiler need attention sooner?
Your boiler usually follows its own schedule.
Except when it breaks down.
Don't wait until the next service if you notice something isn't working as it should.
Watch out for these warning signs
Water pressure keeps dropping: There may be a leak or a problem with a component in the system.
The same error code keeps appearing: Your boiler may have a recurring fault.
You regularly need to reset the boiler: The underlying problem probably hasn't been resolved.
Unusual noises: Whistling, humming or banging can indicate different problems.
Hot water temperature keeps changing: The hot water system may not be working correctly.
Radiators stay cold: Start by checking the thermostat, water pressure and trapped air.
Water appears underneath the boiler: Have the source of the leak investigated.
Soot or discolouration around the boiler or flue: Have the installation checked by a certified engineer.
If your boiler has stopped working altogether, you probably need a fault diagnosis rather than a routine service.
Have the boiler fault resolved →
Noticed a leak around the heating system?
Have a leaking central heating system repaired →
When should you act immediately?
If you smell gas, don't use flames or electrical switches. Leave the building and call the Dutch national gas emergency number, 0800-9009, from a safe location.
If a carbon monoxide alarm sounds or you suspect carbon monoxide exposure, get everyone outside immediately and call 112.
These are not situations where you should wait for a routine service appointment.
What does a heating engineer do during a boiler service?
A proper boiler service involves more than checking whether the heating switches on.
The engineer inspects the condition of the appliance, cleans components where necessary and checks that everything is operating safely and correctly.
The exact work depends on the boiler's make and model.
1. Inspect the boiler and heating system
The engineer checks the boiler's overall condition, visible connections and any signs of leaks or wear.
2. Clean components where necessary
Parts such as the burner, heat exchanger and fan are inspected and cleaned according to the manufacturer's service instructions.
3. Check combustion performance
The engineer checks whether the boiler is burning gas correctly and safely. Measurements or adjustments may be required.
4. Inspect the flue system
Safe removal of combustion gases is essential. The engineer therefore checks the relevant flue components and combustion air supply.
5. Check wear and safety functions
Components are inspected for damage or wear, and the relevant safety systems are checked.
6. Test the boiler and explain the results
After servicing, the engineer checks that the boiler is working correctly and explains whether anything needs further attention.
You'll also know when the next service is recommended.
That's useful.
You don't need to understand every sensor inside your boiler. You just want to know whether it's in good working order.
What do customers say about boiler maintenance through Zoofy?
You book a boiler service. But how do you know whether it's been done properly?
Most people can tell whether a radiator gets warm. Knowing whether the engineer has checked everything correctly is another matter.
Feedback from customers who have booked boiler maintenance through Zoofy shows that clear explanations, honest advice and careful workmanship are particularly appreciated.
An engineer who explains what they're doing
Customers appreciate it when an engineer explains what is being checked, why certain work is necessary and what they should keep an eye on afterwards.
"Good communication beforehand. Clear explanations during and after the work. Took the time to give tips and advice for the future. Very satisfied with the boiler maintenance."
This makes a difference. Instead of simply knowing that someone has worked on your boiler, you understand what has actually been done.
Honest advice about the condition of your boiler
Not every boiler just needs a quick clean to keep running for another few years.
Sometimes a component is wearing out. Or an older boiler may be approaching the point where replacement makes more sense than repeated repairs.
"A really nice engineer who also gave advice on how to deal with the remaining lifespan of our old boiler."
Good advice doesn't automatically mean more work needs to be done.
It means you know where you stand.
Clear communication about additional costs
Customers also value the way an engineer works and communicates, especially when a service reveals that something needs repairing.
"Friendly, knowledgeable and clear about the price of additional work. Satisfied!"
The lesson from these customer experiences is simple: a good boiler service should give you more than a working boiler.
You should know what was checked, whether anything needs replacing and when the next service is due.
Ideally before the engineer leaves.
Why is regular boiler maintenance important?
Fewer unexpected breakdowns
Dirt, wear and faulty components can eventually cause boiler breakdowns.
Regular servicing can help identify problems before the boiler stops working.
That doesn't mean you'll never have a breakdown. But at least you're not waiting for something to fail before discovering it needed attention.
Safety and carbon monoxide
Problems with combustion or the flue system can produce carbon monoxide. You can't see it or smell it.
That's why it's important to have your boiler checked by a certified heating engineer and to install a working carbon monoxide alarm in the correct location.
More efficient heating
A clean, properly adjusted boiler can operate more efficiently than one with dirty or poorly functioning components.
Ask your engineer to check whether the heating settings still suit your home.
Potentially longer boiler life
A central heating boiler often lasts around 12 to 15 years, although some last longer.
Regular maintenance helps identify wear and emerging problems early. It cannot guarantee a longer lifespan, but ignoring maintenance for years is unlikely to help either.
How much does boiler maintenance cost?
Boiler maintenance through Zoofy starts from €129 including VAT.
The final cost depends on the boiler model and the work required. A standard maintenance visit usually takes around one to two hours.
During servicing, the engineer may discover that a part needs replacing. Additional repairs or replacement parts aren't necessarily included in the standard service price.
Ask the engineer to explain any additional costs before the extra work is carried out.
That way, you decide whether to proceed.
View boiler maintenance costs →
Is boiler maintenance mandatory in the Netherlands?
For a typical individual domestic gas boiler, there is no general Dutch law requiring an annual maintenance visit.
However, that doesn't mean anyone can carry out technical work on the boiler.
Since 1 April 2023, work on gas combustion appliances in the Netherlands must be performed by an appropriately CO-certified company.
This includes installation, technical maintenance and repairs.
What about warranties and insurance?
Boiler manufacturers may require regular servicing as a condition of additional warranty coverage. Insurance terms can also be relevant.
Check the manufacturer's maintenance instructions and keep your service records or invoices.
Who is responsible in a rented property?
In rented homes, technical boiler maintenance is generally arranged by the landlord.
Check your tenancy agreement and contact your landlord if you're unsure.
Routine user tasks, such as bleeding radiators or topping up the heating system, may be the tenant's responsibility.
What about apartments and homeowners' associations?
In Dutch apartment buildings, an individual boiler may be connected to a shared flue system.
The homeowners' association, known in the Netherlands as a VvE, is generally responsible for maintaining and checking shared building components, including a communal flue.
If your boiler uses a shared flue system, make sure the condition of that system is also taken into account.
Do you need a boiler maintenance contract?
A maintenance contract can be convenient, mainly because servicing gets scheduled automatically and some contracts include breakdown assistance.
But a maintenance contract isn't mandatory.
You can also book a one-off service whenever your boiler needs maintenance.
When comparing contracts, check what is actually included. Look at servicing frequency, replacement parts, emergency assistance and any additional charges.
Otherwise, you might spend years paying for cover only to discover during a breakdown that the thing you need isn't included.
When is it better to replace your boiler?
A boiler doesn't automatically need replacing because it reaches a certain age.
But if an older boiler keeps breaking down, replacement may eventually make more sense than another repair.
Ask a heating engineer to assess the situation when:
The boiler is around 12 to 15 years old or older.
Breakdowns are becoming more frequent.
Important replacement parts are difficult to obtain.
Repair costs are increasing.
The appliance can no longer operate safely or reliably.
The decision comes down to the condition of the boiler, its expected remaining lifespan and the cost of repairing or replacing it.
Frequently asked questions about boiler maintenance
How often should a central heating boiler be serviced?
Older boilers generally benefit from annual servicing. Some modern boilers only require servicing every two years. Always follow the manufacturer's maintenance instructions and your certified engineer's advice.
Can I maintain my boiler myself?
You can check the water pressure, bleed radiators and refill the heating system according to the user manual. Technical work on the gas combustion appliance must be performed by a CO-certified company.
What is the correct water pressure for a boiler?
For many heating systems, the normal pressure when cold is around 1.5 to 2 bar. The correct pressure depends on the installation, so always consult the boiler manual.
Does a new boiler need annual servicing?
Not always. Some modern boilers can be serviced every two years. Check the manufacturer's instructions, including any conditions attached to the warranty.
How long does a boiler service take?
A standard boiler service usually takes around one to two hours, depending on the boiler and the work required.
What happens if you don't service your boiler?
Dirt, wear and mechanical problems may go unnoticed. Over time, these can contribute to breakdowns, extra repair costs or safety issues. Regular servicing helps reduce these risks.
What if my boiler breaks down after servicing?
Servicing doesn't prevent every possible fault. Note the error code and contact the engineer or company that performed the maintenance. Don't attempt to repair internal boiler components yourself.
Book boiler maintenance before something goes wrong
You could wait until your boiler breaks down.
But boilers rarely choose a convenient moment.
With Zoofy, you can book a heating engineer for boiler maintenance at a time that suits you. Choose your job and preferred appointment time. Zoofy arranges a screened professional, and you pay securely afterwards through Zoofy.
Book boiler maintenance from €129 →
Then your boiler can get back to doing what it's supposed to do.
Keeping you warm.
Without giving you something else to think about.