Top-rated coal furnace manufacturers include the Harman Stove Company, Leisure Line Stove Company and Reading Stove company. These are leading producers in the US, according to Construction-Index.
The Harman Stove Company produces coal stoves which burn pellets, wood, coal, gas, and corn. One benefit of Leisure Line Stove Company models is that wet coal can be burned without putting out the fire or damaging the stove feed system. All of Leisure Line's 10 stove models burn coal. Stoves by the Reading Stove Company are made of cast iron. They can heat a house of up to 1800 square feet in size.
Other good furnace manufacturers include Keystoker and Alaska Stove Company. Keystoker is a Pennsylvania-based company with 60 years of experience. The Alaska Stove Company is a family-owned business, also based in Pennsylvania.