You should always book a boiler service from a qualified licensed gas engineer at least once a year. And while you’re looking for one, ensure that they are Gas Safe certified. This is a legal requirement in the UK, but more importantly if they have the requisite skills for the task, it means that you can be reasonably confident that they have the right qualifications for the task. A qualified technician will be able to work alongside you as part of your on-site team, whilst also carrying out repairs and maintenance as necessary.
The engineer will fit the flue gas and recommend a series of tests to check that everything is in proper working order. This includes an infrared imaging scan, which can detect any signs of wear and tear in the flue gas, and identify any signs of leaks. If you need to make sure that all elements of your boiler are working to their full potential then it is recommended that you employ a gas engineer at least once a year, perhaps more often if you use a gas standby system.
They can also carry out routine checks and maintenance on your boiler, such as checking for loose pipework and ensuring that the flue gaskets are tightened to perfection. You should only ever have one boiler in your house, so it is in your interest to find a team that will work efficiently to allow you to have only one. Hiring an engineer that works in close partnership with your team is essential. They will also offer you advice on the design of your pipework as well as the safe installation of your flue gaskets.