I've looked online and couldn't figure out exactly what I need to do.

I just moved to a new flat and found out that the bathtub drain plug doesn't work well, so water leaves from the bathtub pretty quickly, even when it's "closed". I would like to know what to do to solve the issue.

Here are the facts I have gathered so far:

  • My bathtub is from the brand "Grohe" (and I live in Germany, FWIW).

  • There is a mechanism on the side that makes a small plastic part go up and down (when it goes up, it pushes the drain plug up to open it and when it goes down it just lets the drain plug "fall").

  • The joint on the drain plug doesn't look that bad (at least to my unexperienced eyes).

  • If I really push on the drain plug with my whole weight, the water indeed doesn't flow away.

What I'm a bit puzzled about:

  • If it's a problem with the joint, can I replace the joint alone or should I replace the whole drain plug? Can I buy generic parts or it needs to be the exact same reference?

  • Is it normal that the mechanism on the side to open/close the drain plug doesn't actually pull the drain plug down when closing it? In other words, is it expected that "only" gravity is enough?

Thanks in advance for your help and if you need more pictures, don't hesitate to ask 🙂





  • 1
    If generic parts will work, then by all means use them. Sometimes, though, high end manufacturers (Grohe, as a German import, would be considered high-end in the US, but it may be run-of-the-mill in Germany...) make their parts unique to force you to buy replacements from them. (I'm looking at you, Toto toilets...)
    – FreeMan
    Commented Oct 25, 2023 at 11:40
  • 1
    Also, please clarify whether you're renting or buying the flat. For us Americans, flat/apartment usually indicates a rental - yes, we're difficult that way. ;)
    – FreeMan
    Commented Oct 25, 2023 at 11:43
  • 1
    @FreeMan sorry forgot to mention that, I'm renting indeed :)
    – filaton
    Commented Oct 25, 2023 at 15:35
  • Side note: this type of plug isn't pushed down by gravity alone. When the tub has water in it, the weight of all the water above it is pushing it down with considerable force (the wide disc on top exaggerates this effect). This design may not seal properly when the water level is extremely low.
    – bta
    Commented Oct 25, 2023 at 23:49
  • SOME similar designs DO pull the plug downwards, but many of them rely on some weird twisting or other 'correct assembly' for that to occur - is there any indication that this is the case with this one?
    – MikeB
    Commented Oct 26, 2023 at 14:09

5 Answers 5


As a renter, I'd strongly suggest that a basic generic rubber bath plug (the kind you have to put in place and remove manually) is your best bet.

It will work.

It will cost much less than a Grohe replacement part, which is, frankly, your landlord's responsibility, not yours. But crappy landlords that don't maintain apartments are common.

You can take it to the next apartment, where it will also work, if that landlord also doesn't bother to maintain the tub.

Though actually...

detail of drain

Given where that plug seals, cleaning all the crud from the sidewalls of the drain hole may be most of what's needed to make it seal properly. Particularly the built-up patch of gunk between 3 & 4 O'Clock would defeat the rubber seal and allow water to trickle past.

  • Great point, assuming OP's renting. Not all flats/apartments are rental. My grandparents rented an apartment in NYC for decades, but the building went co-op in the 70s and many people owned...
    – FreeMan
    Commented Oct 25, 2023 at 11:44
  • 3
    It's still cheap and functional if you own the place, but are not too hoighty-toighty about the appearance of the bath hardware, so long as it works.
    – Ecnerwal
    Commented Oct 25, 2023 at 11:49
  • 2
    Even if you are not a renter, I have found that an inexpensive rubber drain stopper works much, much better than anything else. You spend a little bit more for a silicone one, that will last longer and is easier to remove then the conventional rubber ones. I have one with a tiny duck as the handle on top.
    – Questor
    Commented Oct 25, 2023 at 23:30
  • 3
    Clean the underside of the stopper as well.
    – bta
    Commented Oct 25, 2023 at 23:44
  • 1
    I own my place and have done this because in my case the mechanism is shot so the mechanical plug gets stuck in and has to be pried out with a small screwdriver or something. Replacing the whole plug assembly is on my to-do list, but I also know this will be a pain in the neck. Therefore rubber plugs have been purchased until I get time to do the job properly. It'll cost OP maybe a couple of Euro at most and it will absolutely work. This is 100% the answer
    – ThaRobster
    Commented Oct 26, 2023 at 13:02

Some tests/experiments you can perform for free, or at worst, cheap…

Bear in mind you can't get to the push mechanism without at least taking the side off the bath, so you're going to have to live with how much throw it currently has.

First, get some de-scaler [many bathroom cleaners already contain this] & liberally spray the underside of the plug & washer. It's not very scaled but it's worth a try.
As already noted by Ecnerwal, the plug-hole is pretty cruddy too. That needs a clean up as well.

That type of plug has an adjustable 'drop'. In your case the screw/nut on the end - which unfortunately looks like it's already at its shortest.

With the plug out of the hole, drop the white lever mechanism to 'closed' ie dropped. Put a blob of something greasy & visible - like bright lipstick - on the end of the plug, where the screw is. Drop it in the hole. See if it marks the white lever.

If it does, then you're out of adjustment & it can't drop any further. They're wire-driven so you can always push them a bit more closed, as you mentioned.
You could try removing the adjustment screw entirely & see if that gains you enough extra drop to stop it leaking - yet still enough rise so it will empty properly. [There is the possibility of re-jigging this with a different screw… but that's going to be very fiddly to figure out which will fit but have a smaller head...

If you just happen to have some silicone sealant & vaseline [semi-solid grease of any type] - or more lipstick at a push;) run a ring of silicone round the underside of the plug, on the chrome plate, halfway between where the washer ends & the outer edge of the chromed plate. Coat the entirety of the plug hole in vaseline/lippy & spray some water on it.
With the opening mechanism dropped already, drop the plug in the hole, press gently & leave 24 hours.
Temporary new seal - that may even last a couple of years (I've done it before & it's still working well 5 years later, but my plug is slightly more conducive than yours to it adhering well;)

If none of the above works, then take the plug to a good plumber's merchant [not a big high street DIY store] & see if they've got a replacement washer.

Good pictures & explanation, btw.

  • Thanks a lot for the very detailed answer! I'll try what you suggested :)
    – filaton
    Commented Oct 26, 2023 at 10:08

It looks like the black rubber seal is damaged. I am not sure if you can find a replacement seal, but you can definitely buy a replacement plug. Approach a Grohe store.

  • 2
    I'm not seeing it, which pic shows a damaged rubber seal? How can you tell?
    – FreeMan
    Commented Oct 25, 2023 at 12:25
  • 1
    @FreeMan In the image showing the rubber seal from the side, at the top of the rubber on the left side it's clear the rubber has deteriorated from a perfectly round shape. It's not really possible to determine how much damage there is, but there's definitely damage (rubber missing that would exist with a new gasket). Without a better picture, showing both the damage and how that damage mates up to the metal the rubber it supposed to seal against, it's definitely the issue, but the damage is at least something to investigate and resolve.
    – Makyen
    Commented Oct 26, 2023 at 3:31
  • 1
    Given that the OP says it seals fine if you push it in manually, I'm not inclined to agree with this answer.
    – MikeB
    Commented Oct 26, 2023 at 14:07

Start off by cleaning all that crap- which looks rather like plumber's silicone- off the chamfered mating surface of the metal portion in the bathtub.


Check that the central slotted piece is screwed in tightly. I fixed my leaky kitchen sink drain in this way, after finding that the whole plug/drain assembly was slightly loose and could move around, allowing water around the outside. Yours looks to be a similar design.

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