5O) Flame Off!

After clearing the ambush on the School Third Floor, you will find the way to the Rooftop blocked by a wall of flames. Ken will mention you need to go to the Boiler Room and fix the boiler.

Head back to the Cafeteria and go through the red double-doors to access the Boiler Room.

Speak with Thumby, the School's maintenance worker, who explains that the four valves for the Boiler are broken off.

Find the four valves located around the Boiler Room.

Pick up a valve and bring it to the Boiler, then reattach it to one of the empty valve slots.

This action will lock the screen and cause enemies to spawn endlessly.

Hit the valve to turn it to the proper position. Be aware that the valve can spin left or right depending on which side you hit.

When the yellow lines overlaid on the valve disappear, the valve is in the proper position.

Defeat any remaining enemies to unlock the screen.

Repeat steps 5-9 with the remaining three valves to shut off the flames and pop the Achievement.