What happens during a boiler service?

Below is a summary of what typically happens during your boiler service. Hopefully this will help you see what actually happens during the process, as well as provide you with a checklist of items to make sure your engineer covers all the bases.

• A visual check to ensure your boiler still meets current standards 
• Boiler fired to identify any working faults 
• Boiler casing removed to check all main boiler components (burner, heat exchanger, many injector, spark and sensors). 
• Checks to ensure flue terminals are unobstructed and internal flue components are sealed properly 
• Gas valve adjusted to check that the burner is combusting efficiently and properly (normally with using a gas analyser). 
• Inside casing surfaces cleaned 
• Boiler parts cleaned if necessary 
• Gas tightness test conducted to ensure no leaks 
• Boiler casing put back on - checked that it's properly sealed If a primary sludge type filter is fitted cleaned out 
• You should receive a service report that shows everything has been done to maintain your boiler
  

Of course there's a great deal more to it than that, but without becoming a boiler service engineer yourself you probably don't need to know much more! Though the above checklist should stand you in good stead for most boilers, bear in mind that not all boilers are the same.

For older conventional systems, for example, the following would apply:

The pump and expansion vessel would not be contained within a conventional boiler. In most cases they would be near the hot water cylinder.

Parts such as the heat exchanger, burner and fan would need to be dismantled and checked. This would not normally be necessary for the modern boiler, unless the flue gas analysis suggests that there is a problem.

We may also ask if you have a copy of the boiler manual and/or service log. If you don't have a copy of the boiler manual, you can often order these or download them from the manufacturer's website. If you don't have a service log, make sure you keep copies of all paperwork that an engineer leaves with you after every service. These will give each engineer a history of the services, enabling them to more quickly identify any recurring or previous problems.

It is vital that you get a Gas Safe Registered engineer to carry out any gas work you may have and should never, under any circumstances, attempt any kind of DIY gas Work.

Around 250,000 jobs are carried out illegally each year by workers that are not on the Gas Safe Register. By doing this they are putting people's lives at risk. Illegal gas work can lead to a gas leak, fire, explosion and exposure to carbon monoxide, all of which can be fatal.