Reassemble and Tighten Temperature Handle

What happens here

Reinstall the temperature handle onto the valve stem. Align the handle so that when it is set to the desired temperature (e.g., 100 degrees), it points straight up or to the desired position. Insert the Allen wrench into the set screw and tighten it firmly. Do not overtighten, but ensure it is snug enough that the handle no longer wiggles. Once tightened, screw the decorative cap back over the set screw to complete the reassembly.

Goal: Securely reattach the temperature handle to the shower valve stem.