How to Install an Outdoor Furnace

Dispense a 4-by-10 foot concrete pad to hold up the furnace. It should be 4 inches deep. This will also gives you a comfortable place on which you can pack wood in to the furnace.

Excavate a trench below the frost line using a backhoe. This will prevent extreme heat loss and freezing because the ground stays between 45 to 55 degrees F at this level. You can rent a small backhoe if you don't own one.

Place the PEX pipe and the 12/3 110V wire into a 4-by-6 inch PVC pipe. Place the pipe in the trench and run it from the furnace to the house. If you live in an extreme weather environment such as in the northern United States, pack sawdust into the end of the PVC pipe for extra insulation.

Mount the heat exchanger in the outlet plenum of the furnace. Try to locate a size that already fits your plenum so you don't have to do any metal work. You should just be able to make a hole the correct width in the side of the plenum, slip it in place, reseal it and secure it with an L-shaped bracket.

Fasten the PEX pipe on the furnace and the heat exchanger. Use a subsequent run and pump to fasten the PEX pipe to the hot water heater. You won't need a side arm heat exchanger.

Put the circuit breaker into your breaker box. Join the 110V wire/cable to the circuit breaker and the furnace. Install a thermostat and connect it.

Fill the outdoor furnace with water and start a fire.