I'm in Icelabs in part where I have to turn the valve to drain the coolant (see attached image) and in my case, this doesn't happen at all. I've checked Youtube walkthroughs and there, as soon as player rotated the valve, coolant below drained away. But not in my case, preventing me from progressing further. I'm using the community 1.3 patch for obvious reasons.

Anyone else experiencing this? Any idea how to fix it or bypass it so I can continue with the game?

I was forced to use cheats to walk through coolant and after doing like 20-30 meters through it, all of a sudden it drained. Whaaat!? Anyway, now I can continue playing it without God mode the way I played it before. Weird that I seem to be the only one encountering this bug...

I got the same problem until I downloaded the seperate pak5 and pak6 files for the 1.3 fan patch... The game changed TREMENDOUSLY after getting those and the difficulty became something like 3x harder, getting insta-hitscanned and losing 60hp after one pixel of my character turned a corner.

Just came across this bug again (using an early 2018 version of the patch, I thought this issue would be fixed by now)
Anyway, the way to "fix" this is noclip+godmode downstairs through the fluid until you find an enemy down there. That enemy is touching the fluid (doesn't happen everytime for some reason) which prevents the fluid from moving. After you kill said enemy, the fluid will drain as intended. You will be able to progress normally then.
Do you guys know if updated versions of the patch corrected this? (seems to be the case of moving that enemy a few inches back or higher) Is there any point in updating the patch at all since 2018? If there's an easy way to directly update, I will do it.

I just bought the game in GOG (had an old version back in 2000) to give it a full replay. It's version 1.2.
Did 3 complete plays in all 3 difficulty levels without any mods, just as it comes out of the box, and the valve never failed.

I'm just replaying with the 1.3 patch applied and I had to come to the forums because the valve failed and I'm stuck. Did they manage to actually introduce a new bug with the 1.3 patch? What the hell?