Johnson Mfg & Sales Inc.

Johnson Outdoor Wood Furnaces

N5499 County Rd E Ogdensburg, WI 54962
(920)244-7581 or (800)515-4328

Frequently Asked Questions

Q: How far can the unit be from my home?
A: The Johnson Furnace is designed to be outside of the home, away from the house. The usual installation distance is between 50 and 200 feet. An installation location greater than 200 feet from the area you are heating will reflect a loss of efficiency due to the great lengths the water travels. If necessary, this may be compensated for by using a larger diameter of copper pipe instead of the normal recommended Pex-Al-Pex pipe.

Q: How does the furnace work?
A: The firebox is surrounded by water. When the water temperature in the furnace drops below the set temperature on the furnace, the air injection system automatically turns on. Air is then injected beneath the fire and across the top of the firebox to increase burn intensity. Waste materials (smoke and creosote) are burned as fuel rather then discarded smoke. A water baffle in the top of the firebox transfer more heat into the water. A bypass is opened up when loading wood to allow smoke to go up the chimney instead of escaping from the loading door.

Q: How difficult is the stove to install?
A: The Johnson Stove is relatively easy to install by running two pipes between the furnace and the building to be heated. One pipe will be a supply of hot water to the building to be heated, and the other will be a return pipe, carrying cooled water away from the building. Pex-Al-Pex is strongly recommended and has proved to be extremely durable in cold weather conditions. The Pex-Al-Pex should be enclosed in insulation and then housed in PVC pipe for best results. The pipes must be installed at least 24" underground, and 4'-5' if they will be placed where heavy vehicles or machinery may drive over them.

Q: What are the benefits of a Johnson Stove?
A: The Johnson Stove offers the following benefits:
*Clean burn give more heat for less wood
*No more unburned coals
*Wood to gas - gas to heat
*Round firebox design means less welds
*There is none to compare

Q: What is an internal combustor?
A: This totally new technology is so far advanced that it makes even the best of grates and ash removal systems obsolete. This new concept is so more efficient than other designs it's like putting a supercharger in a furnace. Our Johnson with the Internal Combustor burns its fuel so completely, that the job of removing ash is no longer a task. No more unburned coals as seen on energy wasting units, with grates side draft or the draft in the door. Our design is to mix oxygen with the fuel so the coals are allowed to burn to very few ashes for maximum BTU and easy ash removal.

Q: What are your furnace features?
A: Our furnaces have:
*Extra large loading door
*Large firebox
*All controls in one handy location
*Light for night loading
*Anti-flashback door safety catch
*Smoke bypass for easy loading
*Hookup to multiple buildings
*Lockable fire door
*Shutoff switch for blowers
*Easy ash removal-no grates, augers, or ash pans
*Quick temperature recovery time
*All parts precision made
*Weather proof house design
*100% airtight insulation
*Powder coated paint
*12 year limited, prorated warranty

Q: What about smoke?
A: Because our stoves have two blowers smoke is greatly reduced as compared to furnaces that offer a natural draft. The easiest way to control the amount of smoke produced is by the type of wood that you burn.  Dry wood produces less smoke then green wood.  Hardwoods produce less smoke then soft woods.  Burning garbage pollutes the air and voids your warranty.  Burning the furnace year round is never recommended and produces an overwhelming amount of smoke as well as creosote inside of the furnace due to the inability of the fire to get hot enough because enough heat is not called for. The best way to reduce smoke it to only burn dry, hardwood, and only during the heating season when it's cold enough to call for the heat you need.