Run the boiler in this order: Boiler off, Fuel on, Pilot on, Boiler on. Then play the piano keys Mn, Pe, Cn, Ao, Pe. Nothing opens until the boiler is finished, so do that first.
| Step | Boiler Room | Piano |
| Locate | Basement by the briefing room, down the stairs | Right of the mission board, past the fireplace |
| Find the clue | Fuel valve, Boiler valve and Pilot switch on the machine | Blacklight markings on the wall |
| Set the sequence | Boiler off, Fuel on, Pilot on, Boiler on | Mn, Pe, Cn, Ao, Pe |
| Activate | Pilot burns orange, boiler light goes green | Press each key in order |
| Finish | Head back up to the piano | Door on the right opens |
IMPORTANT NOTE:
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October 25, 2026
- Conclusion: Set the boiler to Boiler off, Fuel on, Pilot on, Boiler on and wait for the green light.
Boiler Room Puzzle: Turn Up the Heat and Unlock the Mystery!
The boiler room sits in the basement next to the briefing room — take the door beside it and go down the stairs. The Fuel valve, Boiler valve, and Pilot switch are the three controls fitted around the boiler.
- Turn the Boiler valve off so pressure stops building.
- Turn the Fuel valve on and let gas feed into the system; the machinery responds.
- Turn on the Pilot switch while fuel is running and the boiler is cold.
- Turn the Boiler valve back on; the boiler starts and the puzzle completes once the pressure settles.
The pilot shows an orange glow when it lights, and the boiler light turns green at full power. If the sequence fails, shut the Fuel and Boiler valves off and run the four steps again slowly. Lighting the Pilot while the Boiler valve is still open stops the ignition from completing — that is the usual cause of a stuck boiler.
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Piano Puzzle: Time to Put Your Music Skills to the Test!
The piano is the second half of how to outwit the Boiler Room and Piano puzzles in Black Ops 6, and it only works after the boiler is running. From the mission board head right and pass the fireplace to reach the piano room.
- Grab the black light torch in the room and sweep it around the walls to reveal footprints that lead to a hidden doorway.
- The same torch uncovers the key sequence written on the wall: Mn, Pe, Cn, Ao, Pe. The markings are numbered, so read them from the lowest number to the highest to get the playing order.
- Press the keys in exactly that order — Mn, Pe, Cn, Ao, Pe — and the door on the right opens.
If the piano does nothing, confirm the boiler puzzle is done before changing the notes you press.
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Conclusion
Set the boiler to Boiler off, Fuel on, Pilot on, Boiler on and wait for the green light. Play Mn, Pe, Cn, Ao, Pe on the piano and walk through the door that opens on the right.
The door leads into a hidden lower passage and the rest of the Safehouse chain — a keypad, a computer hack, a lockpick, a radio clue and finally the upstairs safe.
Frequently Asked Questions
What if the boiler puzzle won't complete?
Shut the Fuel and Boiler valves, then repeat the order slowly. Before you light the Pilot, the Boiler valve being left on is the most frequent error.
Why doesn't the piano open the door?
Check that the boiler room puzzle is finished — the piano mechanism stays dead until it is. Then confirm you pressed the keys in the written order rather than every marked key you found.
