The Incinerator gas valve puzzle is one of the more complicated brain-teasers in Signalis, primarily because figuring out exactly what to do isn't immediately clear. There are knobs and a screen with a line graph, and if you turn the knobs, the line graph changes trajectory. But what does it all mean, and how do you solve it to get the Fire Key in the furnace?
This quick Signalis guide will tell you how to solve the gas valve puzzle, as well as how to get the Incinerator key to access the room in the first place.
You'll find the Incinerator room on floor B3, the New Medical Ward, just off of the Morgue on the eastern side of the map. But you'll need a key to access the room. You can get the key from the Sword safe in the Nurse Station off of the South Corridor.
To get the Sword Safe combination, go to the Waiting Room off of the East Corridor, and interact with the note on the chair on the left (west) side of the room.
When you inspect the note, there will be several letters, with a least one scratched out, on the left side, and there will be numbers, with several scratched out, on the right side. The letters on the left side correspond to the numbers on the right side.
Take a picture of the note with your phone, or write the correlations down on a sheet of paper, so you don't have to constantly reference the note in your memory bank while inputting the code. Go back to the Nurse Station, and tune your radio to the correct frequency to get the code. You can view the frequencies by accessing the Frequencies note in your memory bank.
Your note will look different, with the letters and numbers in different places.
Now, interact with the safe. You'll notice that the letters on the safe keypad aren't in the same order they are on the Sword Safe note. Instead, push the letters on the keypad that correspond to the numbers in the code irrespective of their placement on the actual safe.
Enter the right combination, and you'll unlock the safe. Grab the Incinerator key from inside.
When you enter the Incinerator Room off of the Morgue, you'll see a panel and a chamber in the back along the wall. Interact with the panel. Here, you'll see three knobs and a screen with a black line at the top, a red line in the middle, and a green line at the bottom. There are also several indicator lights just to the left of the screen: Co2 up/down, gas up/down, and o2 up/down. There is a lever on the right side of the panel.
The goal is to adjust the knobs so that the black line follows the path of the red line when you pull the lever. If an indicator light glows when you pull the lever, it means you need to raise or lower the associated level until it doesn't glow. For example, if "gas up" glows, you must turn the gas valve down until it doesn't glow anymore, making sure the "gas down" also remains unlit.
The knobs only turn halfway around in either direction. Here's the solution with the valves starting at the center:
Unlike the game's safe codes, it does not appear that this puzzle — or others — has different solutions based on your specific playthrough. With that in mind, this solution should work for you.
With the valves in the right position and the Incinerator puzzle solved, open the furnace, and grab the Fire Key, which you'll need to open the 5-lock door in the Waiting Room, though you'll need to gather four other keys first. Luckily, none of them are as difficult to collect as this one. For more, head over to our Signalis guides.