Stoveheat Premium Smokeless Coal - 25kg bag Stoveheat Premium is a well known & reliable alternative to premium anthracite products. It is ideal to be used in closed appliances including roomheaters, cookers, boilers, & multi-fuel stoves. Stoveheat Premium has a high heat output & a low ash content. It also produces up to 80% less smoke & 25% less CO2 than house coal.