How to Install a Gas Workshop Heater

Just a few weeks into Ron's first winter in Connecticut, it became clear to him that he needed to create some source of heat in his workshop. He didn't need to keep his workshop at a constant temperature, but he wanted the ability to get the heat up quickly when it was needed.

He decided on a unit made just for garages called the Hot Dawg by Modine, which comes in four different sizes: 30,000, 45,000, 60,000 and 70,000 BTUs. The 60,000 BTU model was the size that was recommended for his workshop.

Click Here For a list of what you will need in order to complete this project.

1. Select and prepare location
The unit is designed to attach directly to the bottom of the ceiling joists, but if you want to mount it at an angle, you will need to attach a couple of 2 x 6's to the ceiling joists with lag screws.

2. Hoisting
One of the most challenging parts of this project is hoisting the 80-pound heater up to where it attaches to the 2 x 6's. Begin by wrapping a couple of cargo straps around the heating unit case.

Marine block and tackle is the perfect device to do the heavy lifting. It is designed to hoist very heavy booms on sailing ships it is lightweight yet very strong. The block and tackle is relatively expensive, but it is a lifetime tool.

3. Exhaust system
Because the heater is a gas-burning appliance, you will need to exhaust the gases through a flue. The first step is to attach the T-shaped piece of flue to the back of the furnace. A second piece of pipe attaches from the center of this flue right up through the roof.

You will need to cut a hole in the ceiling that's exactly in alignment with the pipe. Use a plumb bob and move it around on the ceiling until it is centered directly over the flue.

Make a mark on the ceiling at the top of the plumb bob line and then bore through the roof and insert a wire coat hanger to mark the spot so you can locate it when you are on the roof.

On the roof, use a compass to draw a circle six-inches in diameter around the coat hanger using a lumber crayon, and then bore a half-inch hole on the edge of the circle.

Insert the blade of the jigsaw and cut along the line.

Center the large opening of the flashing unit over the hole that you cut in the roof. Then reach inside with the lumber crayon and trace the outline of the oval shaped base of the flashing. Be careful of the sharp upper edge when reaching inside.

Use a utility knife with a hooked blade and cut along the crayon mark.

Apply sealant to the lower shingles, where the base will be sitting on top and then slide the flashing underneath the upper shingles and into the circular cutout.

Finally, secure the flashing base with roofing nails.

The vent pipe has a double wall. The inner liner is made of aluminum and the outside is galvanized steel. The outer jacket of the pipe remains cool even though there are hot gases passing through the pipe.

Pass the pipe up through that flashing and connect the lower end of the pipe to the vent coming out of the back of the heater. The joints are held together with couplings that snap into place.

4. Gas and electricity connections
With the roof installation complete, return inside to connect the heating unit to the gas and electricity. First, apply thread sealant to the gas pipe sections. Tighten them together and finally connect the flexible gas line. (The gas line and shut off valve installation instructions are not included in this project.)

5. Programmable thermostat
A programmable thermostat is perfect in a situation when you don't need heat in the workshop all of the time. With a programmable unit, if you plan on working at 9 a.m., you can set the heat to come on at 8:30 and it will be nice and warm when you come in.

Ron was very glad that he put the unit in. In the few weeks after he installed it, the temperature didn't rise above freezing and the heater did a great job of providing heat where and when he wanted it.