Grohe Valve Problem?

Hi All,
I have a Grohe shower faucet and valve that suddenly has fluctuating temperature and pressure. It's been working fine since installation in 1997. From what I've read, it sounds like a cartridge or other cleanable or replaceable part. My problem is I don't have any documentation or even the model number.

Can anyone give me a suggestion of my next step? How do I find the model number? where can I get schematics?

Thanks in advance!

If you are lucky, they still make that model...take a look at www.groheamerica.com and search the catalog. if it is there, it will have the parts breakdown. Is this a thermostatically controlled valve or a pressure balanced one? Keep in mind, it might not be the valve, it's just that you'd notice pressure variations more in the shower than other places. ARe you on a municipal water system or a local well?

Thanks for the reply, Jim.

I'm on municipal water and nothing else has changed. All pressure is the same in other faucets. I assumed it was a thermostatic valve but now I'm not sure. How can I tell the difference? I've looked at www.groheamerica.com with no luck. I don't find an exact match. I'm willing to experiment trying to repair it before I give up and call a plumber.

Thanks!

It is single handle, or two? Is one of them just a volume control and the other adjusts the temp? If it is single handle, it is not thermostatically controlled. If it is two, it's harder to say. On many of their thermostic trims, there are actually numbers for the temperature.

It sounds like there may be some crud caught in the supply pipes that moves up and down when water is flowing. It may just take removing the cartridge and then turning the water on momentarily to flush the lines out.

Do you have shutoff vavles for the shower control? If they aren't ball valves, the washer could be shot and the pieces are partially plugging the line.

It's a temperature control with seperate volume controls. With my limited knowledge I would suspect the crud issue. Water is slightly hard. So, is the cartridge in the center of the valve? Are any special tools required for removal. I wasn't able to remove anything past the exterior knob (trim & temp ring, etc.). I may need a bigger pair of channel locks if that's all it should take. What about calibration? Is there any trick to that?

Thanks, again. You're a wealth of knowledge.

Sounds like a thermostatically controlled valve. Each one is slightly different, so the best thing to do is probably call or e-mail Grohe. I was able to get the installation instructions from them as a .pdf file. They can probably help you figure out which valve you really have as well. There are really two valves in there, and I'd start with the volume control - you don' thave to calibrate that! On mine, there's a big brass screw down the middle of it...remove the screw then pull it out. Can't say on yours. If you post a picture, somebody may recognize the model and be able to help.

Here's what I've got. The Check Valves are removed and pictured. They obviously needed cleaning, which I've done. I now have pressure back but still have temperature fluctuation. Do these need to be replaced? I still can't get the center section removed. I can't get it to unscrew. Any tips are appreciated.

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