Sublustrum Fourth Valve: Where to Find the Missing Wheel
Find the missing fourth cooling valve in the Sublustrum playtest: the apartment's high cabinet and Echophone scan, with dated community sources.
FAQ
Where is the fourth cooling valve in the Sublustrum playtest?
Do I need the Echophone to pick up the missing wheel?
Should I search the basement for the fourth wheel?
Where is the missing fourth wheel?
Look on top of a high cabinet in the apartment, next to the main capsule. Aim the Echophone at that elevated spot. October replies in “Unable to locate the 4th cooling wheel” report that scanning makes the wheel clickable.
This is community-reported guidance checked on October 13, not a route we have personally played. The thread began during September’s closed test, but the specific apartment correction and cabinet description are October replies. The playtest guide keeps those two test periods separate.

Official promotional image, credited to Brickworks Games / HypeTrain Digital. It illustrates the capsule room, not the exact wheel location.
How should I search for it?
The documented advice supports a short search sequence:
- Return to the apartment and identify the main capsule.
- Examine the high cabinet next to it, including its top surface.
- Aim the Echophone at the suspected item location.
- Once the item is available to interact with, try picking it up.
The replies call the device an “echo-locator” or “location scanner”; the official updates use Echophone. No exact aim angle, distance, key binding or cabinet compass direction is established by the source. Avoid spending time on an invented pixel-perfect route.
Why did another guide send me to the basement?
An early September reply suggested looking high in the basement. Later players corrected it to the apartment, and a further October reply identifies the cabinet beside the capsule. That is why the newer location takes priority here.
The basement is still associated with the cooling machinery. The missing component’s reported pickup location and the mechanism it belongs to are different things. Once you have the wheel, continue with the cooling-puzzle notes; finding it does not establish a final valve combination.

Official promotional image. It illustrates the cooling equipment, not validated valve settings.
What if I can see something but cannot click it?
The strongest repeated point in the October replies is the scanner requirement. Recheck the elevated cabinet while using the Echophone rather than relying on visual inspection alone. We cannot verify an outline colour, sound threshold or other exact success cue.
The developers’ closed-test-results announcement says detection areas and Echophone feedback were improved before the open test. That explains why dated advice matters, but it does not prove that every failed pickup is a bug. The puzzle guide covers the device’s role; use the in-game feedback form or the developers’ discussion channels if the documented location remains unresponsive.

Official promotional image. It illustrates apartment exploration, not the fourth valve’s position.
What should I work on next?
If the instrument is your next obstacle, the piano slider guide records another October community answer. Keep the 2008 Outcry comparison separate from your current test notes: old item routes and puzzle numbers are not automatic proof for a rebuilt 3D scene.
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