Flaming Burst

A flaming burst weapon functions as a flaming weapon that also explodes with flame upon striking a successful critical hit. The fire does not harm the wielder. In addition to the extra fire damage from the flaming ability (see above), a flaming burst weapon deals an extra 1d10 points of fire damage on a successful critical hit. If the weapon's critical multiplier is ×3, add an extra 2d10 points of fire damage instead, and if the multiplier is ×4, add an extra 3d10 points of fire damage.

Even if the flaming ability is not active, the weapon still deals its extra fire damage on a successful critical hit.