CLEANSWEEP chimney sweeping is now an Approved HETAS Chimney Sweep. HETAS is the official body recognised by Government to approve biomass and solid fuel heating appliances, fuels and services, including the registration of competent installers and servicing businesses. A good chimney is essential to the continuing efficient and safe operation of all solid fuel burning heating and cooking appliances. HETAS recommends that chimney sweeping is best carried out by a HETAS Approv