Johnson wood furnaces feature a central control location, a large loading door, a night light, a spacious firebox, a lockable fire door, an anti-flashback safety catch on the door, and a shutoff switch for the blowers. A smoke bypass allows for easy loading and fast temperature recovery.
Johnson wood furnace users enjoy easy ash removal with no grates, ash pans or augers, and each furnace can hook up to multiple buildings. The house design is weather-resistant with 100 percent airtight insulation and powder-coated paint. All parts are precision-made in the United States, and buyers enjoy a 12-year limited warranty. Johnson furnaces utilize two blowers instead of a natural draft to reduce smoke output, and users can further reduce smoke by only burning dry hardwood and avoiding year-round use of the furnace.
Johnson wood furnaces give off more heat with less wood than other furnaces require, and they leave no unburned coals, according to the manufacturer's website. The furnaces work by heating a water tank that surrounds the fire box. The water is then circulated through the user's regular heating system, and waste materials, such as creosote and smoke, are turned into fuel rather than discarded as smoke. Furnaces should be installed between 50 and 200 feet away from the house.