Installation problem: Grohmix shower valve 1 1/2'' extension

The valves are leaking. It's not the shower head itself. Sometimes shower faucets require special tools to service the valves. If you have thought about new shower valves, now would be a good time to replace. Repair may be half the cost of installation of new. In other words, plumber's time to repair or replace is about the same. Get several quotes. TV show This Old House had one on a replacement. It may be available online. Home Depot or Lowes or Ace Hardware may be able to help, Or similar Hardware outlet in your area.

Grohe or AKA Hans Grohe will send you a manual if necessary or if you spell it right you can find a copy online to download. I imagine you missed removing a retainer.

If you spin the shower head off there should be a metal screen inside. If it is clear, Soak the shower head in CLR for about 4 hours. After 10 years even the best water supply will leave behind a build up that can plug the tiny holes.

Before you install the temperature control knob, adjust the valve body (47111) with a wrench to set the temperature to "100 degree or close to it". Now, place the limit ring to tdc (top dead center) and control knob with the red 100-degree align to it. Your problem may have been the valve's temperature setting is out range when you installing the temperature control knob.

SOUNDS LIKE THE CARTRIDGE ASSEMBLY IS BUGGERED UP. PART #46463.
MAYBE THIS WILL HELP:
All parts and finishes of the Delta faucet are warranted to the original consumer purchaser to be free from defects in material and workmanship for as long as the original consumer purchaser owns their home. Delta recommends using a professional plumber for all installation and repair.
Delta will replace, FREE OF CHARGE, during the warranty period, any part or finish that proves defective in material and/or workmanship under normal installation, use and service.
Replacement parts may be obtained by calling 1‑800‑345‑DELTA (3358) or by writing:
Delta Faucet Company Product Service 55 E. 111th StreetIndianapolis, IN 46280

hi try there weeb site grohespareparts.com/ all spare parts are on line

hi there webb page is grohespareparts.com/all spares are on line

Before you install the temperature control knob, adjust the valve body (47111) with a wrench to set the temperature to "100 degree or close to it". Now, place the limit ring to tdc (top dead center) and control knob with the red 100-degree align to it. Your problem may have been the valve's temperature setting is out range when you installing the temperature control knob.

This is typical for an installation without a balanced valve/anti-scald valve on the shower.

If you are using manual on/off valves on the shower, about the only way to fix this is to install the device mentioned in the previous paragraph.