For Faster Service


Specifications, Features and Prices

What are the various models?

Earth offers 5 models:

  • Open System – 1 Door, models 305, 365, 405, 505

Earth also manufactures a forced-air furnace, 305-FA.


What are the firebox specs?

The Earth Cylinder Firebox is 1/2″ Thick (not “almost” as some advertise). Most other companies use 1/4″ thick. Earth is twice as thick!

What are the water tank specs?

The water tank is 10 gauge (1/8″ thick.) Nothing is made light or cheap in an Earth Furnace.

How sturdy are the doors?

The Earth Furnace has a 3 section full-bar hinge to prevent warping.

Can you explain the weight-mass-muscle concept?

The weight of a furnace is the #1 issue you should compare. What do comparable BTU’s weigh?

What exactly is the warranty?

What are the prices?

No One Beats Earth QUALITY or PRICES!

  • Bear Cub Forced Air $5295.00
  • Bear Cub 305 $5850.00
  • Rancher 365 $7500.00
  • Woodsman 405 $7900.00
  • Mountain Man 505 $8500.00

All Furnaces include 1 Taco 3 Speed Pump Installed.

The Furnace Exterior

What colors are available?

Colors available are Black and Charcoal.

What does the furnace exterior look like?

Your furnace will come standard with a corrugated metal covering in your choice of black or charcoal.

Maintaining Your Furnace

How long will my furnace last?

The Earth Furnace is designed to last well beyond the purchasers life! We hope your grandchildren can use it. It comes with a 25 year warranty*.

Bear Cub, Rancher, Woodsman, Mountain Man Owner’s Manuals & Warranties

Bear Cub 305-FA (Forced Air) Owner’s Manual & Warranty

* Bear Cub units come with a 10 year warranty. Please read the warranties for details.

What can break down on my furnace?

There is really not much that can go wrong with the furnace; fans, thermometer, pumps, light switch. But that’s about all.

What is covered under the warranty?

You have a factory warranty on thermostats, pumps, etc. Your warranty on everything from the connections to your house and buildings and in them is between you and your installation contractor. Full descriptions of the manufacturer’s warranties are included in the respective owner’s manuals.

Bear Cub, Rancher, Woodsman, Mountain Man Owner’s Manuals & Warranties

Bear Cub 305-FA (Forced Air) Owner’s Manual & Warranty

What happens if it doesn’t seem to work properly?

If your furnace does not seem to be working satisfactorily… First visit with your installation contractor. Then, if it is not resolved, and you really believe the problem is with the furnace, call us or have your contractor call us and we’ll help in every way we can.

What do I do to regularly maintain my furnace?

Oil all door hinges frequently.

Is there an Owner’s Manual?

Things You Should Know

What size furnace do I need?

  • 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.

How does the outdoor furnace work?

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!

Can I heat my hot water with this system?

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.
  • Install a separate heat exchanger near your hot water heater in your house.

Are there any safety issues concerning the door and feeding the fire?

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.

What can I burn in my outdoor furnace?

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.

What has to be done to install my furnace?

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.)


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.

What exactly comes with my Earth Outdoor Furnace?

  • Digital Thermostat
  • Automatic damper
  • Water Filled Valve System
  • Exterior Light
  • Customized total packages available with heat exchanger, water pump, Pex line, and ball valves

How often do I feed the fire?

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!

What are the cost comparisons between fuels?

You can calculate the difference between fuel sources with the Energy Cost Calculator, developed by Efficiency Maine.

Energy Cost Calculator

Are Earth Outdoor Furnaces a pressurized system?

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.

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How does it work?

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Owner's Manuals | Warranties

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