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Blaze King vs Hearthstone stoves: EPA test data compared
EPA test data checked
Blaze King has 7 and Hearthstone has 13 models certified for sale today. On the EPA's own tests, the typical Hearthstone model burns cleaner, and the typical Blaze King model is more efficient.
| Blaze King | Hearthstone | |
|---|---|---|
| Models certified for sale now | 7 | 13 |
| Fuel | wood | wood |
| Catalytic models | 7 | 0 |
| Top heat output, smallest to biggest | 24,085 to 38,516 BTU/hr | 20,507 to 43,000 BTU/hr |
| Typical efficiency (middle model) | 80% | 79% |
| Typical smoke, as a share of the legal limit | 50% | 34% |
| Cleanest-burning model | Princess PE32 | Green Mountain 60-1 |
| Most efficient model | 30.2 Series | Green Mountain 60-1 |
| Biggest heater | King KE40 | WFP100 |
Closest head-to-head matchups
Each Blaze King model paired with the Hearthstone model nearest to it in top heat output, same fuel.
| Blaze King | Heat / efficiency / smoke | Hearthstone | Heat / efficiency / smoke |
|---|---|---|---|
| Sentry S14 | 24,453 / 78% / 1.4 | Castleton 8031 | 24,540 / 77% / 0.98 |
| 30.2 Series | 36,076 / 83% / 0.81 | Heritage 8024 | 35,845 / 77% / 0.54 |
| 20.2 Series | 31,092 / 80% / 1.05 | Green Mountain 40 Series | 31,581 / 79% / 1.1 |
| 25 Series | 24,085 / 79% / 0.74 | Castleton 8031 | 24,540 / 77% / 0.98 |
| Princess PE32 | 34,435 / 82% / 0.55 | Green Mountain 60 8660 | 33,576 / 79% / 0.6 |
| Princess PI29 Insert | 30,194 / 80% / 1.0 | Green Mountain 40 Series | 31,581 / 79% / 1.1 |
Heat in BTU an hour, smoke in grams an hour.
Every Blaze King model on the EPA list
- King KE40: wood, 38,516 BTU/hr, 81% efficient, 1.0 g/hr smoke
- 30.2 Series: wood, 36,076 BTU/hr, 83% efficient, 0.81 g/hr smoke
- Princess PE32: wood, 34,435 BTU/hr, 82% efficient, 0.55 g/hr smoke
- 20.2 Series: wood, 31,092 BTU/hr, 80% efficient, 1.05 g/hr smoke
- Princess PI29 Insert: wood, 30,194 BTU/hr, 80% efficient, 1.0 g/hr smoke
- Sentry S14: wood, 24,453 BTU/hr, 78% efficient, 1.4 g/hr smoke
- 25 Series: wood, 24,085 BTU/hr, 79% efficient, 0.74 g/hr smoke
Every Hearthstone model on the EPA list
- WFP100: wood, 43,000 BTU/hr, 64% efficient, 1.6 g/hr smoke
- Heritage 8024: wood, 35,845 BTU/hr, 77% efficient, 0.54 g/hr smoke
- Green Mountain 60-1: wood, 35,571 BTU/hr, 81% efficient, 0.51 g/hr smoke
- Green Mountain 60 8660: wood, 33,576 BTU/hr, 79% efficient, 0.6 g/hr smoke
- Green Mountain 80-1: wood, 33,424 BTU/hr, 80% efficient, 0.53 g/hr smoke
- Green Mountain 80 8680: wood, 33,396 BTU/hr, 81% efficient, 0.67 g/hr smoke
- Manchester 8362: wood, 33,038 BTU/hr, 78% efficient, 0.65 g/hr smoke
- Clydesdale 8492: wood, 32,588 BTU/hr, 79% efficient, 1.16 g/hr smoke
- Mansfield 8013: wood, 32,200 BTU/hr, 78% efficient, 0.54 g/hr smoke
- Green Mountain 40 Series: wood, 31,581 BTU/hr, 79% efficient, 1.1 g/hr smoke
- Bari 8171, Bari Plus 8172: wood, 26,036 BTU/hr, 76% efficient, 0.94 g/hr smoke
- Castleton 8031: wood, 24,540 BTU/hr, 77% efficient, 0.98 g/hr smoke
- Lincoln 8060, Green Mountain 20: wood, 20,507 BTU/hr, 79% efficient, 1.1 g/hr smoke
This compares EPA lab results only. It says nothing about price, build quality, warranty or dealer support.
Source: EPA Certified Wood Heater Database, currently certified room heaters, checked Nov 1, 2026.