Gas Safe Register 
Gas Safe Register is the official list of gas engineers who are registered to work safely and legally on boilers, cookers, fires and all other gas appliances in United Kingdom, Isle of Man and Guernsey.
HETAS Ltd
HETAS is the official body to approve biomass and solid fuel domestic heating appliances, fuels and services. including the registration of competent installers and servicing businesses.
OFTEC
OFTEC is a trade association that works on behalf of the oil heating and cooking industry in the UK and Republic of Ireland, representing the interests of manufacturers, suppliers and training providers. OFTEC also takes a lead role in setting industry standards and manages a competent person registration scheme for technicians who install, commission and service oil and renewable heating and cooking equipment.
National Association of Chimney Engineers
The National Association of Chimney Engineers (NACE) was formed in 1982 by a group of independent companies specialising in chimney lining. Their purpose was to set and enforce national standards of workmanship and quality in this demanding sector of the construction industry.
