Wood stoves & other home heating

Washington regulates the types of wood stoves and other wood burning devices allowed for sale, resale, exchange, or that are given away. They must meet federal EPA and Washington certification standards. 

Use a stove that is certified in Washington, the right size for your home, and properly installed. Never install a non-certified wood stove. See the list below of approved wood burning devices:

• Wood stoves that meet Washington standards
• Pellet stoves that meet Washington standards
• Fireplaces that meet Washington standards
• Masonry heaters that meet Washington standards
• Wood-fired hydronic heaters that meet Washington standards
• Wood-fired furnaces that meet Washington standards

Stoves must also meet standards for the amount of fine particles coming from the device during testing.
 

Type of Device	Washington PM2.5 Limit	EPA PM2.5 Limit
Catalytic* wood burning device	2.5 grams per hour	4.1 grams per hour
Non-catalytic** wood burning devices	4.5 grams per hour	7.5 grams per hour
Factory-built fireplaces and masonry heaters	7.3 grams per kilogram	no limit

*Catalytic devices reduce smoke by using a ceramic element to burn it.
**Non-catalytic devices use other engineering to reduce smoke output.

Emission testing requirements for wood stoves

All wood heaters (wood stoves, pellet stoves, etc.) made after 1939 must be emission tested unless they meet the definition of a wood-fired cook stoves. Heaters that also bake or cook do not qualify as wood-fired cook stoves. 

In order to sell wood heaters they must be tested at an EPA certified lab using either a Category A - EPA approved method, or Category B -  EPA approved alternative method.

Once testing is complete, email the wood stove coordinator:

• The make, model, and efficiency rating.
• A copy of the test summary.

The wood stove coordinator will review your information and contact you if more information is needed. Approved devices will be posted on this page under "certified wood stoves."
 

Type of stove	WA emission rate standards	Additional information
Wood stoves, coal stoves, and corn stoves	2.5 grams/hour for catalytic stoves.   4.5 grams/hour for non-catalytic stoves.
Pellet stoves	4.5 grams/hour.
Manufactured fireplaces (also known as low-mass fireplaces or zero clearance fireplaces)	7.3 grams of fine particles per kilogram of test fuel.	Test the fireplace at an EPA certified lab using Washington's fireplace test method. If a fireplace contains features to control the air to fuel ratio, it is considered a wood stove, and must be tested and approved as a wood stove.
Indoor wood and pellet furnaces	2.5 grams/hour for catalytic furnaces  4.5 grams/hour for non-catalytic furnaces
Masonry heaters	7.3 grams of fine particles per kilogram of test fuel.	Test the masonry heater at an EPA certified lab using Washington's fireplace test method. Manufacturers may apply for an exemption from testing if a testing lab establishes a device is substantially similar in design to an already tested device. A Washington-approved process for this is available through OMNI-test labs.
Outdoor wood-fired boilers (residential)	n/a	Wood-fired boilers are not legal in Washington State. EPA Method 28 OWHH is a Category C test not officially approved by EPA or Washington State.

Wood-fired cook stoves that are used primarily for cooking must have the following characteristics to be exempt from emission testing:

• A device for measuring oven temperatures
• A flame path that is routed around the oven
• A soot clean-out door below the oven
• An oven with a volume of 1 cubic foot or greater and an oven rack
• No fan or heat channels used to dissipate heat from the appliance
• A cooking surface measured in square inches or square feet that is 1.5 times greater than the firebox
• A portion of at least four sides of the oven will be exposed to the flame path during the oven heating cycle, while a flue gas bypass will be permitted for temperature control
• An ash pan

Those seeking to install wood-fired cook stoves must follow local codes and ordinances. Work with your local building permitting department to meet local requirements. Contact your local Clean Air Agency to understand potential limits to using your cook stove during burn bans.

Consider other heating options before you buy or install a wood stove. Natural gas and electricity are much cleaner ways to heat your home. Use a wood stove or fireplace that is certified in Washington, the right size, and properly installed:

• A quick guide on How to select a new stove for home heat (video)
• How to operate your wood stove more efficiently (video)

Many cities, counties, housing authorities, and utility companies offer grants, low-interest or interest-free loans, and/or free weatherization and conservation programs. Check with your local clean air agency for more information.

Removing an uncertified wood stove is not required when you are buying or selling a house. To help protect air quality, we encourage you to use cleaner home heating options, such as electric or natural gas, and recycle uncertified wood stoves.

However, selling an uncertified wood stove on its own is illegal. Wood stoves are certified when they are manufactured. A homeowner can not apply to have a wood stove certified.

• Burn only wood — Illegal materials include garbage, treated or painted wood, particle board, plastics, rubber, waste petroleum products, animal carcasses, asphalt products, paints, chemicals, or anything that normally emits dense smoke or unacceptable odors.
• Burn dry, seasoned wood — Use wood that has been split and covered for at least one year.
• Allow air in — Don't overfill your stove with wood or damp down your fire. This robs the fire of oxygen, produces less heat, wastes wood, and creates more smoke.
• Make minimal smoke — A properly burning fire will emit very little smoke. Smoke coming from your chimney should be no more than 20 percent opacity. You can test the moisture in your wood by using a moisture meter.