When you need work done on your home by a professional tradesperson it is important for you to know that you can trust that person. Trust them to know what they are doing and to do a good job for the right price.
The following may come in useful when searching for a plumbing engineer. Check that they are a member of a recognised industry body. These include the Chartered Institute of Plumbing and Heating Engineering (CIPHE), the Association of Plumbing and Heating Contractors (APHC) and Gas Safe Register.
For gas installations in the UK you must by law use a gas engineer on the Gas Safe Register.
Chartered Institute of Plumbing and Heating Engineering (CIPHE) is the professional body for the UK plumbing and heating industry.