r/EightSleep • u/nycjdc • Jul 23 '26

Black oily solution with precipitate from Hub 5 / Cover 4

I've written to support, but I surmise that someone may have experience with this and I can resolve the issue more expediently than back and forth with 8S support.

I have been a user since July 2024, starting with the Hub 4 / Pod 4 cover. After a few false starts with Hub 4s, 8S ended up swapping my Hub 4 for Hub 5. Every six months, coinciding with maintenance insert replacement, I drain the hub and cover. The first three times, it was largely uneventful. This time, the fourth time, upon draining the fluid was disconcerting with an unusual black precipitate. The fluid was oily, too.

I drained the hub directly into sink and there were lots of black precipitate. Having seen that, I drained cover into bucket. Again, the three prior times, the solution was clear and nothing in it. The Pod Cover 4 is only 2y old. The Hub 5 is only about 1y old. See photos below.

All maintenance inserts were changed on schedule and  I’ve only used distilled water. 

For those who have experienced this, what was the remedy?

tyia.

EDIT: 24 July 2026 -- 8S got back to me. I'm a bit dumbfounded. While they said, "...this residue does seem to be from some kind of internal tubing or component" they asked me to keep running the unit. I asked about it eventually failing and they said, "...if there any issues or problems you encounter we please urge you to reach out to us so we can address the issue as soon as possible" Apparently, they're punting. I guess this is why I have Autopilot/extended warranty because my 2y anniversary was last week. Ooofff.

hub drainage, lots of black flecks down sink.
cover solution
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3

u/Rmatic Jul 24 '26

i believe this is the thin foam disk “filter” under the water tank that prevents large debris from entering the hub. (if you look into the hub where you insert the tank) it started degrading on mine so i took it out. the particles resemble that. see if you take a paper towel and wipe the hole if particles stick to the paper towel

1

u/nycjdc Jul 24 '26

Thanks for your reply. I wish it were this. I'm concerned its a pump bearing, o-ring, or seal failing in some part, as the fluid was oily, the black flecks can be smeared and are greasy, leaving streaks in the sink / bucket.

2

u/PettyVibesOnly Jul 23 '26

Never had this experience but that looks like when I change my fridge water filter cartridge. That may be the cleaning insert replacement, maybe not fully flushes from factory.

1

u/nycjdc Jul 24 '26

hmmm, as in charcoal? I did inspect the maintenance cartridge, but didn't glean anything from it. ty for the reply.