TOM'S TECH TIPS
Grohsafe 35 016 vs 35 033
A few of times a year, I’ll get a call from a showroom or plumber who says “My customer is not happy with their new shower/hand shower set. What can I do to make them happy?" My question is then (even though I’m already sure of the answer), “What valve did you use?” The reply is usually “Why the GrohSafe™ 35 016 000 Pressure Balance Rough-In Valve Outlets with Built-In Spring Loaded Diverter, of course!” (or words to that effect).
I’ll reply “Bummer, dude.” Because that's just the kind of sympathetic, understanding person I am.
Because unfortunately, this valve is not made for a shower/hand shower. It’s made for a shower-over-tub-spout, but still people sell them for shower/hand shower combination. My advice: Don’t!
In “the good ol’ days” with 2.5 gpm shower heads, you could use this as an economical way to make a shower/hand shower combination. But as shower head flow rates have decreased from 2.5 GPM to 2.0 to our current 1.8 or less, the back-pressure on the diverter (from the restricted flow rate) makes it nearly impossible for the user to switch from hand shower to shower, and back again. This means that every time the user turns on the shower valve (because the plumber has installed the hand shower out of the bottom [default] outlet), water comes out of the hand shower. The user tries to pull the diverter button, but can’t (too much back pressure) – and the user is unhappy.
The user can turn off the valve temperature handle, then pull the diverter button, and then turn the temperature handle back on. But this uses two hands and a contortionist.
Oddly enough, I have some thoughts on the subject. (You're shocked, I’m sure…)
And this is why you come to me! For all the Grohe info and wise-guy commentary you can handle.
Thanks, Tom S