How to Heat a Garage Workshop

How to Install a Heater in a Garage Workshop

1. Working with gas is extremely dangerous and should only be left to a licensed professional.
2. Shut the gas off at the meter.
3. Determine a location to mount the heater that’s easily accessible to the gas line. To give the heater more range, try mounting it in a corner.
4. Mount the bracket for the heater to the chosen location using bolts and a drill. Be sure to follow the instructions to ensure proper clearance from the walls and ceiling.
5. Slide the heater onto the mounting bracket and secure it with nuts that come with the heater.
6. Drill a hole into the wall or ceiling using the drill with a spade bit to connect the gas piping.
7. Screw the mounting bracket provided with the heater into the wall or ceiling using the drill and some drywall screws.
8. Connect the flexible gas line to the existing gas line and then pass it through the bracket.
9. Thread the fitting and brass connection that come with the heater onto the flexible gas line and then screw the fitting onto the bracket.
10. Connect the flexible gas line to the heater using a variety of gas pipe, fittings, elbows, and nipples. Use pipe dope to secure all the connections.
11. Drill a hole on the other end of the garage and install a vent to ensure there is another air flow to allow exhaust to escape the room.
12. Connect the thermostat to the heater and attach it to the wall.
13. Turn the gas back on.

Safety Note: During a This Old House garage heater installation, the licensed gas fitter on the project emphasized that working with gas lines requires proper credentials: “You need to be a licensed gas fitter.” Even with pre-cut pipe lengths simplifying the assembly, never attempt gas line work yourself — always hire a licensed professional to make and test all gas connections.

Pro Tip: When deciding where to position your garage heater, resist the urge to mount it directly above your workbench. As explained during a This Old House garage workshop project, placing the heater in a corner and angling its wide aperture allows it to cover the entire space — reaching 15 to 20 feet in each direction — rather than just warming one spot.

When running new gas pipe, you no longer need to cut and thread every piece on site. Pre-cut black steel pipe is now available in lengths from 1 to 6 feet, in half-inch increments, making it possible to build your gas line like an erector set. This approach, demonstrated during a This Old House garage workshop installation, saves significant time and reduces the need for specialized threading tools.

Learn More: How to Remove an Old Fuel Tank

Resources:

Richard installed the High Intensity Radiant Workshop Heater, manufactured by Mr. Heater.

The other materials Richard used to install the heater, including the gas piping, the flexible gas line, and the plywood to hold the bracket for the heater, can all be found at home centers.

Expert assistance with this segment was provided by Echols Heating and Cooling.

For workshops where a radiant heater like the one Richard installed isn’t practical, another option is a hydronic radiant floor system. This Old House has featured retrofittable radiant systems using cross-linked polyethylene (PEX) tubing and above-subfloor heat-transfer panels, such as the Wirsbo Quik Trak system, which can be installed over an existing subfloor without major demolition. These systems pair with a dedicated boiler and zone valves for efficient, even heat distribution across a garage slab or workshop floor.

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