How do I adjust the water level in the toilet bowl itself? With flushing there is a gush of water that actually flies forward and onto the floor, not really ideal. I think it's because the level of water inside the bowl is too low but I have no idea how to adjust this...a more traditional toilet, no problem, but this one it too high tech for me!

  • Hello, and welcome to Home Improvement. Would you add a picture of the inside of the toilet? And, you should probably take our tour so you'll know how best to participate here. Sep 13, 2019 at 12:44
  • 1
    The bowl level is dictated by the trap height (u bend) if there is not proper venting it may get sucked down lower, on standard toilets during the tank refill a small amount is added to the bowl. Is yours a tanked model or pressure vessel type.
    – Ed Beal
    Sep 13, 2019 at 14:32
  • It has a blue plastic tank behind the wall, this much I know...but now that it's built-in, I'm guessing there is no way to adjust the trap height as you have mentioned :(
    – Ian
    Sep 14, 2019 at 17:06

2 Answers 2


The geometry of the toilet bowl itself determines the water level, so it’s not adjustable. Try adding water with a bucket and you will see the surface area return to where it was designed to be. The flush action is designed to get as much force out of the six liters of water as possible, so there will be turbulence. I recommend closing the lid before flushing. With European toilets, it seems to be a matter of us adapting to them.

  • Thank you, it's too bad this is the way, I should have researched this type of toilet more but it looks so much better with the bulk of it hidden behind ceramic tile...having drops come flying out even with the lid closed is not so pleasant!
    – Ian
    Sep 14, 2019 at 17:01
  • @Ian Sorry to hear. Is this a dual flush toilet? If so, does the water splash out when the smaller volume button is pressed?
    – Tjalsma
    Sep 14, 2019 at 23:46
  • Hello there, it is a dual flush and with your question in mind, I went and flushed with the larger button and it did not splash! Coincidental perhaps, but for now I'll tell my kids to only use the BIG button :) Not good for water conservation but better to avoid cleaning the floor...thanks for your comment!
    – Ian
    Sep 15, 2019 at 17:01
  • @Ian That makes me think something is amiss with the mechanism. You can take off the plate covering the actuator and peer down into the tank. Does anything look out of place?
    – Tjalsma
    Sep 18, 2019 at 19:13

I had the same problem, and I called Grohe support, and they gave me a flow reductor free of charge. It doesn't completely OK, but kind of a solution. If you search for 'Grohe 42300000' online, you'll find the piece.

  • Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know the details of contributing here. Nov 6, 2020 at 14:58

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.