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Vaillant Boiler Service & Maintenance

Rob Wells
By: Rob Wells
Updated: 3rd February 2023

Arranging an annual service for your Vaillant boiler could help to extend its life, potentially heating your home for up to 15 years.

A boiler service helps to keep the unit running efficiently and safely, as well as bringing any potential issues to the attention of an engineer before they have chance to worsen.

What is a boiler service?

A heating engineer will need to be hired to carry out a boiler service and involves them carrying out various tests and inspections in and around the unit. The heating engineer must have the appropriate registration for the type of boiler they're working on, this means that gas boiler should be serviced by a Gas Safe engineer and oil boilers by an OFTEC engineer.

All Vaillant boiler are fuelled by gas, which means that a Gas Safe engineer will need to be hired for the service. You can find a list of registered engineers on the Gas Safe Register website and you should always ask to see their Gas Safe ID card as soon as they arrive.

From start to finish, a thorough boiler service should last no less than 30 minutes. Depending on the type of boiler and whether the engineer comes across any faults, they service could be longer.

Boiler service checklist

When you've checked the engineer's Gas Safe ID card and you're happy that they're competent enough to begin the service, they will run through some standard checks. Here's everything you should look out for:

  1. A visual inspection of the boiler, checking for any signs of corrosion or leaking as well as a blue pilot flame.
  2. Removal of the casing so that they can inspect and clean the parts: heat exchanger, burner, main injector, safety devices and spark probe.
  3. Checking that the flue terminals are free of any obstruction as well as being safely installed. They should also make sure that seals, water and gas pipework are all undamaged.
  4. They should take readings of the gas pressure and flow settings, ensuring that they're at the correct level.
  5. To round of the service, the engineer should put the boiler into operation so that they can check for any running faults and issues with the temperature controls.

After the service, the engineer will leave you with a service report, highlighting everything that they've done. Make sure to check that they've done all of the above. If you're uncertain about anything that they've done don't hesitate to ask any questions, they'll be happy to help.

Is your boiler due a service?



Why is it important to service your Vaillant boiler?


A boiler service is the opportunity to make you aware of any potential safety issues, such as a carbon monoxide leak. As an odourless and colourless gas, carbon monoxide can go undetected and lead to serious health problems. Any concerns about how your boiler is operating, especially if you notice that the flame is an orange or yellow colour, and you shouldn't hesitate to contact a Gas Safe engineer. Don't wait until your next service is due.

Keep heating bills low

Something that's important to most when it comes to the central heating is keeping the bills as low as possible. During a boiler service, the engineers will make sure that all of the components are running efficiently, helping to save you money for longer.

Prevent breakdowns

What might appear a small issue with the boiler could one day become a major fault. Identifying potential faults before they grow into something bigger is an important part of a boiler service and could save you from a large repair bill at some point in the future.


To keep your Vaillant boiler warranty valid, you're required to have the unit serviced by a Gas Safe engineer once every 12 months. Vaillant boilers have a standard warranty of 2-5 years but if your boiler was installed by a Vaillant Advance Installer then it could be as long as 7-10 years. Don't get your boiler serviced by a qualified professional and your warranty will end early.

Get a Benchmark Checklist from the engineer once the service is complete to prove to Vaillant that the warranty is still valid.

How much does a Vaillant boiler service cost?

For a one-off boiler service you're looking at the total cost falling somewhere between £60 – £120. There are several factors that will have an impact on the final bill though: your location (London tends to be the most expensive), boiler model, age of the unit and, ultimately, the engineer carrying out the service.

It's possible to save money on the service by arranging it during the summer months when heating engineers are likely to be quieter. In addition to saving some money, you will know that your boiler is ready to heat your home when winter arrives.

You should NEVER attempt to service a boiler yourself – always hire a Gas Safe registered engineer.

Is your boiler due a service?



Boiler service plans

Instead of paying a one-off fee for a boiler service, you can take out a boiler service plan, or boiler cover, for a period of 12 months. During this time, you would pay a fixed monthly fee that includes a boiler service and required repairs.

In total, a boiler service plan is likely to cost over £100 so you could well be better off paying one-off fee, especially if your boiler is still under warranty. However, if your boiler is any older than 8 years and no longer under warranty then it's worth considering as you're covered in the case of an unexpected breakdown.

Having a Vaillant boiler means that you can join the Vaillant Maintenance Service Plan, entitling you to 12 months of boiler cover. Vaillant list the main benefits of the plan as:

  • A boiler service
  • Annual repairs up to the vale of £1,500
  • Replacement boiler up to £750 if your boiler can't be repaired
  • Official Vaillant boiler spare parts

Boiler maintenance

As well as the service, you can carry out some checks yourself to make sure that the boiler is running as it should all year round.

Insulate your pipes

With pipes being susceptible to freezing during the winter months, you should get them insulated. Otherwise, you boiler could have high pressure, begin to leak or even breakdown completely.

Monitor the pressure

The ideal boiler pressure should read somewhere between 1 and 1.5 bar and you can check this yourself by looking at the pressure gauge. The reason that it's important to check is because over time, pressure can drop, meaning that the boiler might struggle to ignite. Should your boiler need repressurising, then you should check the instruction manual provided by your manufacturer.

Insulate your home as much as possible

You can have a brand new Vaillant boiler on the wall but if your home isn't well insulated then you won't feel the full benefit and it will have to work extra hard to warm you up.

Annual servicing

Taking care of the boiler yourself will only get your so far and should only been done as well as an annual boiler service, not instead of one. It might be tempting to put off a boiler service because of the price but a little bit of research can go a long way and you could come away with the perfect deal for you.

The best way to save money on a boiler service is by comparing quotes from multiple engineers. That way you know that you're getting a good price for your area. Get a free quote for a fully-qualified Gas Safe engineer in your area for your next Vaillant boiler service.

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Rob Wells

About the author

Rob Wells

Rob is another of our resident home heating experts. He manages our external partnerships, making sure you get the most up to date information.

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