Where to Find a Blaze. Blaze can only be found in the Nether Fortress Biome, all throughout the base due to their spawner being in the fortress itself. Their spawner is commonly found in small rooms with a staircase.
Spawning. Blaze spawners can be found only in Nether fortresses and will start spawning blazes once a player gets within 16 blocks. The mob spawners have a chance of spawning 1-4 blazes at once. Blazes can only spawn in light level 11 or lower (at the lower half of their body).