Missing Part for Grohe 34-436 Thermostat Shower Valve

[kjo]

Hi all - I got a fantastic deal on a new Grohe 34-436 shower valve this week. I'll spare you the details, but in a word, I can't take it back and am stuck with it. The problem is that before I committed, I didn't notice that there was a part missing. I'm guessing it is a small black or red button that must be depressed to turn the thermostat past 100 degrees. Where the button should be, there is a slot, with a white plastic post that sticks up through the temperature scale indicator ring. In the exploded parts diagram, this would be part #1 "Chrome grohmix scale handle". I can't see the button on the parts diagram, nor can I see it on any picture I've seen of this fixture. I'm not even sure if there IS a button there, but it just doesn't look right.

Could someone verify that there is supposed to be a button there and maybe tell me what it is supposed to look like? Also, can you offer an opinion as to whether the fixture will be adversely affected if that slot is just left open, because I sure as heck am not going to pay 75 bucks for that part number just for that button. Could you also tell me whether that button truly needs to be depressed before the scale ring will turn past 100 degrees? A bit of extra pressure and it turns for me. The springs seems to be loose enough that it doesn't really require the button. Any advice for making this very expensive fixture not look like it was robbed for spare parts would be appreciated. Thank you in advance!

[jadnashua]

Mine has a button, it appears that recently they changed that to a detent that just requires more torque to adjust past the detent. On mine, you'd physically break something it you tried to move it past the stop. Not sure when they made that change, or if it is universal across their line. Have you tried calling their 800 number?