Every stove gets a score from 0 to 100% built from five factors, which maps onto the 5-point rating shown on the site (a 0% score would be 1.5 stars; a perfect score, 5). Each factor is scored against fixed reference points, not against the other products in the list, so adding a new model never moves another model’s rating. Stoves are grouped by type, wood stoves, pellet stoves or inserts, and each group has its own price scale.
| Factor | Measures | Weight |
|---|---|---|
| Efficiency | EPA tested share of the fuel's energy that reaches the room | 30% |
| Value | price per 1,000 BTU of EPA tested heat output | 30% |
| Emissions | EPA certified smoke particle emissions | 15% |
| Warranty | warranty length | 10% |
| Convenience | log length and blower for wood; hopper burn time and controls for pellets | 15% |
Where the numbers come from
Efficiency, emissions and heat output come from each model’s EPA certification test, from the EPA certified wood heater database or the maker’s spec sheet and manual quoting it. Every model on these pages is on EPA’s list of stoves certified to the 2020 standard. Price, warranty, log length, hopper size, burn time and controls come from the maker’s product page, manual or warranty, or the maker’s own copy on its Amazon listing.
Why advertised BTU isn’t used
Makers often advertise a maximum output, such as 85,000 BTU, worked out from how much wood the firebox holds rather than measured. The EPA test measures the heat a stove actually delivers at its lowest and highest burn rates, and those figures are usually far lower. Value uses the EPA tested maximum, so every stove is measured the same way. The advertised figure and coverage claim are still listed on each product page.
The factors
Efficiency is the EPA tested efficiency, the share of the fuel’s energy that ends up as heat in the room, on the higher heating value (HHV) basis the EPA uses. HHV counts the energy in the water vapor the fire makes, so it reads several points lower than the “lower heating value” figures some ads quote. 60% scores zero and 80% full marks. Some models list only EPA’s default efficiency, a stand-in value rather than a test result; they get the neutral middle score.
Value is the current price divided by the EPA tested maximum heat output in thousands of BTU, on a log scale for each group, so going from $40 to $20 per 1,000 BTU counts as much as going from $80 to $40.
| Group | Scores 0 | Full marks |
|---|---|---|
| Wood stoves | $60 per 1,000 BTU | $15 per 1,000 BTU |
| Pellet stoves | $70 per 1,000 BTU | $20 per 1,000 BTU |
| Inserts | $90 per 1,000 BTU | $25 per 1,000 BTU |
Emissions is the EPA certified rate of smoke particles, in grams per hour, on a log scale. Since 2020 the limit for new stoves is 2.0 g/h (2.5 g/h when tested with cord wood). 3 g/h scores zero and 0.5 g/h full marks. Less smoke means a cleaner burn, less creosote in the chimney and less smoke for the neighbors.
Warranty is the longest warranty on the stove body or firebox: 1 year scores zero, 10 years or a limited lifetime warranty full marks. Parts such as glass, gaskets, blowers and igniters are usually covered for less; the product page notes what each warranty covers.
Convenience depends on the fuel:
| Wood stoves | Share | Pellet stoves | Share |
|---|---|---|---|
| Longest log it takes, 14 in (zero) to 22 in (full) | 60% | Longest burn on one hopper, 12 hours (zero) to 48 hours (full) | 50% |
| Blower: included full, optional half, none zero | 40% | Thermostat control | 30% |
| App or Wi-Fi control | 20% |
What isn’t scored
Coverage claims, advertised BTU, firebox volume, flue size, mobile home approval, dimensions, weight and looks are listed but not scored. Size matters most: pick a stove whose EPA tested output suits your space, and a type that suits how you’ll use it, before comparing scores. Independent tests are listed where they exist, but there are too few to score.
Missing data
If a figure isn’t published, that factor gets the neutral middle score (50) and the product page marks it as estimated.
Ties and discontinued models
Products are ranked by score within each group. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.