Need Grohmix expert, temp prob

Discussion in 'Shower & bathtub Forum & Blog' started by LynnC, Jan 8, 2010.

  1. LynnC

    LynnC New Member

    Messages:
    4
    Location:
    Wisconsin
    I have a Grohmix valve that has really never worked well. After years of not being able to control the temp much and messing around with it, I decided it must be a Paraffin Cartridge issue. These are quite expensive, so I bought a whole new valve instead of paying more for all the parts I probably needed to swap out. Anyway I pulled it all out..except the part welded in. I put it all back with the new parts and I can not get cold water to go through the valve. I dismantled it all and can get cold to the stop valves, and to the pipe that holds the Paraffin Cartridge, but when I put the cartridge in, no cold water will pass.

    Hot water comes through, but no cold. Of course this happens on a Friday night...although I suspect local plumbers wouldn't have a clue about this kind of thing anyway.

    Common questions people seem to ask...yes the hot is on the correct side, water pressure is good on hot and cold.

    Thanks for any ideas...I'm stumped and kind of tired of putting this together/pulling apart, although I seem to be getting pretty good at it.
  2. LynnC

    LynnC New Member

    Messages:
    4
    Location:
    Wisconsin
    an idea about the Grohe valve

    Ok, not many ideas here...I'm wondering if there are multiple ports from the stop valve to where the paraffin cartridge goes. If this is the case then maybe one is open, but the one where it goes to the mixing chamber of the cartridge could them be blocked. These openings between the stop area and cartridge is not very obvious...sort of thin openings from what I can see using a flashlight and feeling around.

    Sorry if this is too esoteric a question...something just isn't lining up right if no cold water can pass.
  3. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,809
    Location:
    New England
    Sorry I can't be of any help. Try calling the manufacturer on Monday. I really don't want to tear mine apart to see how it works! Note, on most of those valves, there's a brass debris screen on the water inlet. Some valve housings also have integral service stops. Make sure the stop is fully open and there's no crud blocking the flow on the inlet filter screen.
  4. LynnC

    LynnC New Member

    Messages:
    4
    Location:
    Wisconsin
    Grohe issue

    Yeah this is beyond all the screens. I have the stop valves out (they are new anyway) and the shutoffs are what I ease open to check if the water will pass to the bathtub spout. I plug the stop valve hole on the hot side and it passes to the spout. I plug it on the cold side and get a face full of water. Somehow between the stop valve and the paraffin mixing valve there is a problem on the cold side.

    I'll call Grohe on Monday and report back if I figure it out...just for someone else's sake later. This seemed like the most with-it forum on Grohe valves, so I thought I'd give it a shot. I actually learned a lot about how to work with them on this forum.

    later
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,809
    Location:
    New England
    In addition to the thermostatic cartridge, it is possible it also has a pressure balance spool valve. That could be stuck. Turning one supply on without the other doesn't help, if that's the case...it would jam the spool valve to one end, and if it is sticky, may not return properly if dirty or worn.
  6. LynnC

    LynnC New Member

    Messages:
    4
    Location:
    Wisconsin
    Fixed the problem...I'm pretty sure

    Turns out I was talking to my daughter about the problem and she said, "Well the sink doesn't have cold water either." And I got to thinking about when that 1920's vintage pedestal sink had a leaky cold faucet...you know the old hot and cold separate....and it seemed easier to just shut it off than get a rubber gasket that would actually stop the leak. And then I remembered how the cold water feed to the tub has a tee that went under the tub over to the sink.

    So long story shorter I opened the sink cold tap, ran all the orange water out while running the shower and wallah...it works. I don't understand all the physics, but the one seems to have affected the tub valve. I get cold water, and the hot is a nice hot for a shower. whew

    Thanks for your patience and help in this...strange one
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