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Signalis: How to open the 5 Lock Door

And solve the Incinerator Room and Pump Room puzzles.

Signalis is a survival horror game through and through, which means that not only will you be fighting to stay alive, but you’ll be solving plenty of puzzles, too.

During the second portion of the game, after you finally access the elevator shaft, you’ll soon come across a mysterious door that requires five keys before it’ll open. Some of the keys for Signalis’ 5 Lock Door are certainly easier to get than others, and the others will require your puzzle-solving skills.

To save you roaming the corridors and becoming victim to various infected Replika and Protektor models, we’ve detailed how to open the 5 Lock Door in Signalis, and solve the Incinerator Room and Pump Room puzzles in the process.


How to open the 5 Lock Door in Signalis

Signalis’ 5 Lock Door requires five different keys to open, which should come as no surprise. The five keys needed are as follows: Fire Key, Blank Key, Water Key, Air Key, and Gold Key.

The Blank Key will ultimately be used to forge the Earth Key, but we’ll explain that in more detail later.

How to solve the Incinerator Room puzzle and get the Fire Key in Signalis

To get your hands on the Fire Key, you’ll first need to find the Incinerator Room key, which can be found in the Sword Safe. By now, you should have the document which contains various radio frequencies which will give you each safe code, however, the Sword Safe is a little different.

Refer to radio frequency 237.000, and you’ll be given a code for the Sword Safe: 48434. Then, you’ll likely find that the input pad for the Sword Safe is, in fact, letters.

Now, if you read the note in the Waiting Room, where the 5 Lock Door is located, you’ll find a note titled ‘Sword’. This gives you a cipher to crack the code for the safe, and your numbers will translate as the following code: H?HBH. Now, the only letter that is blanked out in this note is F, making our full code for the Sword Safe as follows: HFHBH.

A cipher for the sword safe code in Signalis

Go to the Nurse Station, and pop the code in on the Sword Safe. This will give you the Incinerator Room key, and an Eidetic Module. It’s also worth noting that your initial code from the radio could very well be different to mine; in that instance, use this guide as a mere indicator of what to do next.

Head on over to the Incinerator Room using the new key, and you’ll encounter the Incinerator Room puzzle here. Essentially, you need to set the correct levels of CO2, Gas, and O2, for the incinerator to open. You can easily do this with a little trial and error, and the lights to the left of the machine will tell you each time which component we need more or less of.

Failing that, my answer is in the image below!

The solution to the Incinerator room puzzle for the Fire Key in Signalis

Once the Incinerator Room puzzle is solved, the incinerator will open, and you’ll acquire the Fire Key.

How to solve the Pump Room puzzle and get the Water Key in Signalis

Next up, you’ll want to head into the Protektor Bathroom, which you can view on the third floor map below.

The map of the third floor in the facility in Signalis

From the Protektor corpse in here, to the right of the bathroom stall, you’ll find the Pump Room Key. Next, using the map above again, make your way to the Pump Room.

In here, you’ll find a puzzle that is all about draining water. Your goal, ultimately, is to have the same amount of water in both A and B.

This particular puzzle can feel rather obtuse, and it’s difficult to get there using trial and error alone. Fortunately, a document in the Pump Room details exactly what order you need to move the water in, albeit in a very convoluted way.

The solution for the pump room puzzle in Signalis

For your reference, here’s the order to follow to get the same amount of water in both A and B:

  • A to B
  • B to C
  • C to A
  • B to C
  • A to B
  • B to C
  • C to A

With the puzzle complete, the Protektor Bathroom will now be drained of water. Head back into the room, and you’ll now find a hole that you can jump down; head on down, and you can collect the Water Key from a table in the next room.

How to use the Blank Key and get the Earth Key in Signalis

First things first, make your way to the Imaging Room on the third floor of the facility. Here, you’ll find an X-Ray machine with five objects you can look at.

Navigate to object D; this is the item you want to focus on. Put the machine in X-Ray mode, and rotate the item until you can see the pattern on the card clearly. Here, you can use your Eidetic Module to make a note of the pattern, or you can do what I did: screenshot it, and write it down.

Item D in the X Ray machine in Signalis

Now, go to the Flooded Store Room on the fourth floor and retrieve the Blank Key if you haven’t already. Then, head back up to the Office on the third floor where the Card PC is. Using the PC, you’ll want to print a pattern on the Blank Key.

The pattern on the Blank Key needs to match Item D from the X Ray machine, and if you’re still struggling to get it right using the screenshot or note you took, the solution is embedded below.

The solution to the card printing puzzle involving the Blank Key in Signalis

Print the card and retrieve it again, and then this will act as the Earth Key needed for the 5 Lock Door.

How to get the Gold Key in Signalis

Once you’ve access to the Pipes room, you’ll be able to make your way to a few different levels of the facility in Signalis. To get your hands on the Gold Key, you’ll want to head to the fourth floor, and then to the Sleeping Ward shown on the map below.

A map of the fourth floor of the facility in Signalis

In here, you’ll find a Video Tape. You’ll then need to take this tape to the VCR Player, which can be found in ICU 01 on the third floor of the facility. Play the tape, and you’ll enter a form of dream sequence on a train.

Advance forward on the train towards a person. As you get close, the lights will flicker and the person will vanish, but the Gold Key will be left behind in their place. Grab it, and the dream sequence will end.

How to get the Air Key in Signalis

To get your hands on the Air Key, you’ll need the Examination Room Key, and a Socket Wrench. The Examination Room Key can be found on the fourth floor, in the Flooded Office room.

Take this to the Examination Room on the third floor, and you’ll then find a 10mm Socket on the desk in here. Next up, make your way to the Store Room and collect the 10mm Socket Handle from here. Then, go into your inventory and combine the two items to have the Socket Wrench at your disposal.

Then, make yourway to the fourth floor, and go into the Vent Room that is just beyond the Sleeping Ward (where you found the Video Tape earlier). You’ll be able to use your Socket Wrench on the vent at the back of the room, and then, you can collect the Air Key.


That’s it for the 5 Lock Door, and good luck with what comes up next. I’ll give you one clue: attack when it’s crouched. Good luck!

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