Do you need to be qualified before you can install a boiler? For gas-fired boilers, the installers you engage must be Gas Safe registered (previously CORGI) as a safety and legal requirement, and they should also be trained in the installation of condensing boilers. For oil-fired boilers, you can employ an Oil Firing Technical Association (OFTEC) registered installer or a reputable installer who is capable of installing condensing boilers as per the paragraph above. OFTEC members are approved to certify that their work meets building regulations. If you employ an installer who is not registered with OFTEC, you will need to tell your local authority building control department before the installation work starts.