Hi everyone.

We have a question that we're hoping someone can help with. We are installing the Grohe Atrio 19 167, which is a dual handle shower faucet; the top handle is water control and the bottom handle is temperature.

The installation instructions say to remove the ceramic headpart that comes installed on the rough valve (for the water control) and replace with the ceramic headpart in the box. We think that the one that came installed says 70 degrees (hard to read through the wall). The one in the box says 90 degrees.

We don't have any problem following instructions, but we just want to understand why we're doing this in the first place.

Thanks for any insight - Mary Ann and Dave