Boiler Service Checklist

A boiler service is a yearly inspection and test to ensure your boiler is operating effectively. All boiler manufacturers advise using it.

What is a boiler service?

A boiler service is a yearly inspection and test to ensure your boiler is operating effectively. All boiler manufacturers advise using it. If you don't service your boiler once a year, your boiler guarantee will be null and invalid. It would be best if you thus serviced your boiler every year. 

To ensure everything is safe, visual checks inside and outside the boiler and flue, as well as practical tests using gas testing techniques and equipment, will be performed.

In addition to cleaning any elements that may require cleaning, a boiler service should inform the homeowner of any suggestions the engineer feels are necessary for the boiler or heating system. Only Gas Safe Register engineers are qualified to perform boiler maintenance. 

A service company or competent installer licensed and certified to do maintenance on your boiler or combustion-related equipment should inspect your boiler once a year or at startup.

You can't do it by yourself. A boiler service certificate may also be required for your records. A boiler certificate indicates that your boiler was serviced by a Gas Safe licensed engineer and is safe to use. You can only get this certificate from an engineer registered with Gas Safe.

Boiler service checklist

Is your boiler having problems? The following are warning signs or can also be put on our boiler service checklist that a gas appliance may soon stop operating:

  • The pilot light frequently blows out

  • You must often restart your boiler.

  • Your central heating system's water pressure is continuously increased.

  • Inconsistent heating of the radiators

  • Variations in the hot water temperature when it is being used. 

  • An increase in boiler noise

  • The boiler shows signs of soot or discolouration.

Early boiler maintenance is usually a good idea for the following reasons:

  • It's unquestionably safer to be prepared for a boiler maintenance expense.

  • An advanced boiler maintenance arrangement will protect you from unexpected expenses at the moment of emergency.

  • Less likely for your boiler to malfunction.

  • No unforeseen charges will have to be handled if your boiler goes wrong in any case.

How long does a boiler service take?

It usually takes around 30 min to an hour, and the price range for a 30-minute boiler servicing is between £60 and £75. In terms of boiler service, customers have two choices. They have two options: make a one-time payment or get boiler insurance. Costs for the boiler cover range from £150 to £350.

What does a boiler service include?

  • Ask the customer about known difficulties or concerns with the central heating system's boiler and controls during the preliminary boiler visual inspection.

  • Perform a visual inspection to ensure that the appliance or boiler, its placement, and its central heating system adhere to current regulations and the manufacturer's specifications.

  • Before beginning work on it, look for any damage.

  • The appliance's consumer controls and safety features operate as intended.

  • The flame is functioning correctly (if possible)

  • Electrical wiring is secure with the necessary distances between combustibles and the boiler and complies with manufacturer specifications.

  • Ensure that the gas supply piping is installed correctly and has adequate clearances.

  • If ventilation is necessary for the room where the appliance is located, ensure it is adequately ventilated and follow the boiler manufacturer's recommendations.

Service for central heating: 

The central heating system has to be serviced periodically for optimal performance. Since it is pivotal to your home’s heating system, the following steps need to be done diligently for an effective service.

  • Check there are no cold patches in the radiator valves that might cause improper functioning.

  • Ensure the timers on the heating system work well

  • Check water pressure is in the safe pressure range (approx. one bar).

  • Install CO and smoke detectors to get alerted of any smoke or gas emission.

Examine and clean the gas injector (s)

  • The boiler pilot assembly, gas injectors, and spark electrodes should be removed and cleaned. Examine the ignition leads' condition and replace them if necessary. 

  • Inform the customer of the charges if components are needed. 

  • Check for leaks and soot, clean the heat exchanger and reinstall, assemble, and inspect the seals.

Test disturbed gas joints for leakage. Repeat the whole gas tightness test on the gas supply.

Check the functionality of the thermocouple before starting the boiler and test all gas flame failure and safety devices attached to the boiler (flame supervision device). 

Checks the status of the boiler

Check the flame picture for proper operation once the boiler is running once more, and then, after about five minutes, check the inlet working gas pressure, which should be around 20 w.c./Millerbars (according to a reputed source)

Finally, check the gas burner pressure or perform a gas rate to determine how much gas the boiler is burning and whether it is within the manufacturer's specifications.

Adjust as necessary Check/test the flue for issues/correct functioning using a gas flue analyser, flue flow tests, and spillage tests and verify the flue terminal's proper positioning, size, and termination details.

After checking

Fill out a service certificate, landlord certificate, or gas safety certificate.

Apply the Industry Unsafe Situations Procedure as necessary, and give cautionary alerts or safety advice if appropriate.

Combi boiler service

A combi boiler is a single device that warms hot water and your central heating system when you turn on the heat or use any of the DHW outlets.

In UK households, combi boilers are the most prevalent kind of boiler.

A combi boiler, or combination boiler, combines the two operations of heating your radiators and producing hot water into a single wall-mounted or floor-standing machine.

There is no need to heat cylinders full of water that may not be utilised since combi boilers heat your radiators on a sealed, pressurised system and heat your mains water as needed. In case of larger houses, the procedure might differ. 

Optimal Time to get your boiler checked

As long as the sun is out, April through October are the best months for inspections! To avoid having too much time pass between receiving the check and using it, it would be ideal to wait as late into the summer as possible. 


Reading the boiler's owner's handbook is one of the keys to keeping it in good working order. Be sure to follow any special directions the manufacturer may have provided regarding your particular boiler throughout this procedure. If at all feasible, have a copy of your boiler's startup/inspection handbook on hand so you can always refer to it.

You should notify the service technician immediately if you see any issues or concerns. 

Contact a gas safe boiler technician near you

With a boiler cover plan from Smart Cover, you can avail benefits from boiler and central heating coverage. This will serve as a monthly or yearly insurance policy to cover your boiler.

Embark on a journey to understand the intricacies of boiler replacement timelines with our insightful blog on "How Long Does It Take to Change a Boiler?" Gain clarity on the factors influencing the duration of this essential home upgrade.