NEW! Demonstration Videos

We've just added three, short videos demonstrating the Earth Outdoor Furnace.

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Things You Should Know

A guide to what to expect from your furnace and how to use it most efficiently. Also, safety issues and concerns are covered.

No, this unit is not a pressurized system, it is an open system. Capping vent could cause serious damage to the unit and/or personal injury. Capping the vent pipe under any circumstance will void your warranty.

You can calculate the difference between fuel sources with the Energy Cost Calculator, developed by Penn State Extension.

Energy Cost Calculator

Burn Time - Facts and Fiction

  • "Burn Time" is a term used to gauge the time your furnace will operate before re-loading it with fuel.
  • Be very careful about deceptive "Burn Time" advertising!
  • The Facts: "Burn Time" is affected by several factors:
    • How many square feet are you heating?
    • Daily temperature variations and fluctuations.
    • Type of water system (Pex) you install.
    • Distance from the furnace to the home.
    • Incline of water flow.
    • Type of fuel and amount of moisture in the fuel you are burning.
    • Insulation quality and value of the house or building.
  • The Truth is... most furnaces, you will have 12-18 hours burn in average conditions, so figure on putting in fuel in morning and evening. If you have your furnace in a handy location like I do, I fill it before I get in my truck to leave and fill it when I get home before I go in for the evening. In severe cold and wind chill weather, you may need to fill before going to bed at night.
  • These are the facts and truth. The main thing is... make it handy. Enjoy your furnace. Save money! Keep your home cleaner and safer! Enjoy that consistent, even, steady comfort and warmth, and smile when you want to turn the thermostat up!
  • Digital Thermostat
  • Automatic damper
  • Water Filled Valve System
  • Exterior Light
  • Customized total packages available with heat exchanger, water pump, Pex line, and ball valves

Your new furnace arrives completely wired with plug-in, air bleed valve mounted and thermostat set. We recommend your pump be mounted and wired (for an additional charge.)

View Photo

All you have is 4 connections to make!

  • 1. 1" Pex outgoing at bottom of pump.
  • 2. 1" Pex return port at bottom.
  • 3. 1/2" water source line (coupling).
  • 4. Electric to plug in box.

Only Burn Approved Materials

Caution! Never burn materials which are not approved for your furnace. Residential furnaces are coal-burning only and Commercial furnaces burn wood only. According to Federal Regulations they must be used for these purposes only. It is prohibited to use a Commercial unit in a Residential application.

  • First, it negates your warranty.
  • Second, there could be substances that could cause combustion, or otherwise damage to persons, property, or the furnace.

Opening Your Furnace Door

  • Your furnace is equipped a double latch safety system and 18" handle. When opening the door the latches will "catch" before completely opening.
  • If you burn only approved materials, you should never have any "blow back" when you open the door.
  • It is unlikely in the Earth Furnace to ever have "blow back"... but it is always wise and prudent on any type of furnace to be aware of any potential and use reasonable care when opening.
  • Always keep your facial area away from or close to the door area. That fire is hot! Sometimes a rush of air on a simmering furnace can cause pretty quick combustion. Always use caution.

Your furnace is capable of heating your hot water for your home. We suggest one of these two methods.

  • Order your furnace with a copper coil on the inside to which you hook your hot water line.
    ~OR~
  • Install a separate heat exchanger near your hot water heater in your house.

How The Furnace Works

  • The firebox is surrounded by water.
  • That hot water is pumped (by a small pump located either on your furnace or in your house) through a pipe loop to the heat exchanger in front of your blower fan.
  • The blower fan blows the radiated heat from the hot water into your duct system, into your home for clean, non-dry, even, comfortable heat.
  • The "heat-reduced" water returns to your furnace, is re-mixed with the "hot" water, and continues the circle, providing you with consistent, clean, efficient heat that won't dry out you, or your home!
  • You can utilize your existing blower, duct work, and house thermostat!
  • BTU usage is the critical factor.
  • Example: If you are using (1) 20"x20" coil, that is 140,000 BTU + Domestic Hot Water Heat Exchanger that is 80,000 BTU, then you need a 220,000 BTU furnace
  • Don't under-size yourself. Better to have a little extra than too small.
  • Talk to your dealer, or our factory, and do an estimate on your BTU usage before you order.