Gas Mark 1 are a Selby based plumbing service carrying out all types of plumbing work. We are a Corgi Registered company and employ ex British Gas engineers who are all highly experienced. Whether you are looking for a new boiler installation, boiler repairs, combi-boilers, central heating systems we are the company to help. We offer a 24 hour call out service and cover a large area around Selby. Call us in confidence today. Specialising in the installation, repair, servicing and maintenance of gas boilers.