Grohe Thermostatic Shower Valve - No "Off" Position

Discussion in 'Shower & Bathtub Forum & Blog' started by Nonlinear, Jun 6, 2020.

  1. Nonlinear

    Nonlinear New Member

    Joined:
    Jun 16, 2017
    Location:
    Toronto, Ontario
    We just renovated a bathroom with Grohe shower components (19988001 thermostatic shower valve, 35026000 rough-in). I've attached a picture of the rough-in installation.

    When the shower valve was installed and the water was turned on, there was no "neutral" position where the water could be shut off. There would either be a decent amount of water coming out of either the overhead shower of the hand shower no matter where the adjustment lever was pointed.

    Our contractor said the cartridge was bad, so I called Grohe and they send me a new one within a week. With the new cartridge installed it is 99.5% fixed, but unfortunately there is still a very very slow dribble of water out of the hand shower when the adjustment lever is in the neutral position.

    Does it seem possible that two brand new cartridges would have this problem? I'm worried that there is something wrong behind the walls, but with my low-level understanding of the rough-in box I can't understand how that could be the problem.

    Any advice is appreciated.
     

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  2. Marlinman

    Marlinman In the Trades

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    Last edited by a moderator: Jul 12, 2020
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  4. Nonlinear

    Nonlinear New Member

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    I believe that trim kit is for an overhead shower only, we have both an overhead shower and a hand shower.

    Our problem is that when the "water direction" lever is put to the 6 o'clock position there should be no water going to either the overhead shower or the hand shower, but this is not the case. The temperature lever seems to be working fine.
     
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    New England
    On some of the Grohe volume/diverter cartridges, there's a very fine adjustment you must perform to get it to not provide water to either of the outlets. The system has splines on the shaft, you may need to move it slightly to the next notch to get it to stop flowing when it is in the 'off' position. On the one I have, it took a few trials to get it right when I replaced it. The original one lasted about 15-years before it started to drip a little. They're not cheap, and Grohe doesn't give out new cartridges for devices that old like say Delta does as they consider that normal wear, not a defect.

    On the one I have, it is a tub/shower volume control/diverter. The stop allows you to turn it to the tub spout without doing anything...to get it to the shower, you turn it the other way after pressing in the button for the stop.
     
  6. goda

    goda New Member

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    Location:
    Mississauga
    I am facing a similar issue with a newly renovated bathroom with the same rough-in (35026000) but using a different thermostatic shower valve (19947000) - a slow dribble of water is coming out of the HEAD shower (not the hand shower like in your case), when the lever is in the off position.

    I've tried emailing and calling Grohe but have not been able to get ahold of them. Can you let me know how you managed to get in touch with them and have them ship you a new cartridge?

    This is my 3rd installation with the same rough-in and valve. The first one was also having issues and was able to replace it (7-8 years ago). The second one worked fine, so it seems it's a hit and miss with these cartridges.
     
  7. goda

    goda New Member

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    Sep 28, 2020
    Location:
    Mississauga
    The splines are in their notches when the handle is in the 'off position' yet the shower head still leaks slightly. I've even moved the lever slightly to the hand shower open position (few mm), and the head shower still leaks.

    Can you elaborate on what valve you have and how you performed the adjustment?
     
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
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    Occupation:
    Retired Systems engineer for defense industry.
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    New England
    The volume control on mine has a stop on it. You can turn the volume up and it comes out the tub spout. If you turn it back to the stop, the water stops. If you want to use the shower, you have to press in a button that will let you then turn that same volume knob the other way beyond the stop and the water comes out the shower head. The knob's stop position is controlled by a cam, and that came fits on the shaft that has notches, so you can adjust where it literally stops. Finding the sweet spot between tub and shower took a few trials. Your valve uses a different control, so I don't know how it is supposed to work.

    If you do not have the instructions, call Grohe and they can email you an electronic copy.
     
  9. goda

    goda New Member

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    Thanks for clarifying. I've had a real difficult time getting ahold of Grohe here in Canada. Have called them multiple times, left voicemail, and sent emails with full details on the problem and no response so far...disappointing. Will keep trying.
     
  10. Nonlinear

    Nonlinear New Member

    Joined:
    Jun 16, 2017
    Location:
    Toronto, Ontario
    After the first replacement cartridge was leaking (slow dribble from the hand shower) I called Grohe and they sent another replacement cartridge. This cartridge (second replacement, third overall) also had a slow dribble leak, this time from the overhead shower.

    At the end of my rope, I called Grohe Canada again and said I need someone with a PhD in their products to troubleshoot this problem. They shipped us yet another cartridge (this is the third replacement, fourth overall) and told me they would send one of their plumbers to install it. Well, this latest cartridge also has a slow dribble leak, again from the overhead shower. The plumber first thought it might me residual water in the lines but we were able to rule that out by closing the service stops, observing that the leak stops, opening the service stops, and observing the leak resumes.

    At that point the plumber said he would escalate the issue with Grohe and we are waiting to hear from someone there. In the meantime, I just want to ask the experts here if I am understanding things correctly.

    If anything was wrong with the brass rough-in (maybe inner diameter machined too big or not concentric?), or if anything was wrong with the O rings on the cartridge at the 3, 6, 9, and 12 o'clock positions (shown in picture), water would be leaking through the front of valve, is this correct? If one of the two water inlet O rings was leaking, I can't see how water would find it's way around the back of the cartridge and past one of the outlet O rings to get to the hand or overhead shower.

    The fact that there is no water leaking at the front of the valve through the space between the cartridge and the brass rough-in tells me those O rings are sealing fine. If this is the case and water is leaking from the overhead or hand shower it must be something in the "guts" of the cartridge that is not sealing properly.

    It sounds like goda has the same problem, different valve part number but uses the same cartridge (47853000) so I'm "glad" it's not just me. Any advice or experiences from other people experiencing similar issues is appreciated, I just want this problem resolved so we can finally complete this renovation.

    FYI for anyone else in Canada experiencing this problem, the number I have been using to contact Grohe is 905 271 2929.

    cartridge1.JPG
    cartridge2.JPG
     
  11. goda

    goda New Member

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    Sep 28, 2020
    Location:
    Mississauga
    Hey Nonlinear,

    This is hilarious as I was having the same issue you are having. Grohe was very difficult to get a hold of but each time they would just send a new cartridge for me to try. Every time I installed a new cartridge either the shower hand or the head would leak/dribble.

    In the end I realized what Grohe seems too ignorant to - the O ring rubber that goes all the way around MUST be greased before putting it in. Even though their installation instructions or videos on YouTube don't mention this step, it's in their maintenance instructions for when you have to take it and put it back in! Unfortunately they don't ship grease with the cartridge or trim. I pleaded with them to send me their grease (Grohe Syntheso LM 220) which they funny enough include with their Grohtherm Smartcontrol valve trim, but instead they sent me another cartridge.

    I tried putting in plumber's grease that I bought from HomeDepot (Moen was the brand), but it too could not create a good seal. I ended up getting a professional grease for bearings, and valves (NLGI grade 2), which did the trick! The grease has the consistency of toothpaste, and allows you to put it around the O ring all around the perimeter of the cartridge.

    Their products are great, it's just unfortunate that their installation instructions and videos are misleading and inaccurate.

    Hope that helps you out!
     
  12. Nonlinear

    Nonlinear New Member

    Joined:
    Jun 16, 2017
    Location:
    Toronto, Ontario
    An update on this in case others searching the internet for troublesome Grohe cartridges wind up here.

    The local Grohe plumber, on a tip from someone at Grohe USA, installed an older cartridge. Lo and behold, there are no problems now. The thinking is that there was a bad production run of cartridges. All the leaky cartridges we had were shipped to Grohe in Illinois for testing.

    From my limited experience, the problematic cartridges seem to have a light grey plastic base (the end with the inlets and outlets that slides into the rough-in). The older model cartridge that was installed with no problems has a black plastic base.

    If it is a bad production run I hope Grohe can sort it out quickly, who knows how many of these potentially leaky cartridges are out there.
     
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