Reuben Saltzman

Are furnaces allowed in bedrooms?

Every home inspector probably wonders this the first time they see a furnace in a bedroom. Or to take this question a step further, is it legal to install any type of gas appliance in a bedroom? Yes, it’s legal and safe to install a gas appliance in a bedroom, but there are a lot of little requirements to make it legal. Today, we’ll dig into those requirements.

Fuel Gas Code

If you want to find the rules for combustion appliances, you can find most of the requirements in the Fuel Gas Code. Here in Minnesota, we use a single book that combines the mechanical codes and fuel gas codes into one, which you can find online here. To find the rules for what type of appliances are allowed where and under what conditions, we turn to section 303, which talks about appliance locations.

Section 303.3 of the code says that gas appliances may not be located in the following locations:

  • Sleeping rooms
  • Bathrooms
  • Toilet rooms
  • Storage closets or surgical rooms
  • In a space that opens only into such rooms or spaces

But then it goes on to list a handful of exceptions, saying you can install gas appliances in these locations as long as you meet any one of the following requirements:

  1. The appliance is a direct-vent appliance installed in accordance with the conditions of the listing and the manufacturer’s instructions. This means you have an appliance constructed and installed so that all of its combustion air comes directly from the outside, and the exhaust gases are discharged directly to the outdoors. A common example of this would be a high-efficiency furnace with a two-pipe system. You can have a high-efficiency furnace installed with only one pipe… but that would not be a direct-vent installation. Another example would be a modern gas fireplace; most of those have a two-pipe system as well.
  2. Vented room heaters, wall furnaces, vented decorative appliances, vented gas fireplaces, vented gas fireplace heaters and decorative appliances for installation in vented solid fuel-burning fireplaces are installed in rooms that meet the required volume criteria of Section 304.5. In short, you can install one of these specific appliances as long as you have a really big room. You need 50 cubic feet for every 1,000 BTUs. For example, you could install a 30,000 BTU gas fireplace in a room with at least 1,500 cubic feet. For a room with 7′ ceilings, that would mean you’d need about 215 SF of floor space.
  3. Deleted.
  4. Deleted. Sections 3 and 4 both refer to very low-BTU unvented room heaters in bedrooms and bathrooms. Unvented gas appliances simply aren’t allowed here in Minnesota, which is why this section is gone. If you’re outside of Minnesota, you can find these exact requirements in section G2406.2 of the IRC.
  5. The appliance is installed in a room or space that opens only into a bedroom or bathroom, and such room or space is used for no other purpose and is provided with a solid weather-stripped door equipped with an approved self-closing device. Combustion air shall be taken directly from the outdoors in accordance with Section 304.6. 
  6. A clothes dryer is installed in a residential bathroom or toilet room having a permanent opening with an area of not less than 100 square inches (0.06 m2) that communicates with a space outside of a sleeping room, bathroom, toilet room or storage closet. This last one was recently added to allow for gas clothes dryers in bathrooms.


You can have a furnace installed in a bedroom as long as it’s a direct-vent installation, or you can have it tucked away into a separate room opening to the bedroom as long as you have a solid weather-stripped, self-closing door. If you go that second route, you also need to have combustion air added to the room.