Make sure to seal the threads of the pipe that the tub spout gets connected to with the teflon tape. Make sure to put 3-5 coatings of teflon tape in the direction of the rotating the tub spout for a tight seal.

If you paid a professional to install it and you touch it before calling them back then you've just eaten it. Any reputable contractor will correct a problem whether it's their labor or the product itself. If you try to repair it they can wash their hands and walk away.

raaj123,

Across which threads do you think water leaks for 30 minutes and then stops?

It would be very hard to put in a shower valve so shoddily that it drips for half an hour. Enormously difficult unless the valve came faulty or was was damaged in installation. However, some valves, particularly pressure balancing ones, are so delicate (picky? fussy?) that you need to follow pretty strict limits on pipe sizes, lengths, and shower head height.

Someone's going to need to look at this who knows his or her stuff. Before they come, find the installation instructions they left with you.

How drippy are you talking?
Is this maybe an issue with an air valve?
I know that sometimes my hand wand shower head water drips back through (ie, drains) through the tub spout... and that can take some time.

Thanks all. Sorry it's taken so long to respond. I was doing some experimenting the last few days after coming across an old thread on another site. (See last two posts in the link below.)

Kirkhall seems to have hit upon the issue; my old setup had the diverter in the tub spout, with the shower hose screwed into the spout, while this doesn't. So, now it looks like the water gets "backed up" after we shower unless we manually turn the diverter to the spout. As a result, if someone then goes to take a bath (at least the same day--I have no idea if it would be different if we waited 12 or 24 or 48 hours between a shower and a bath) the water continues to drip out the tub spout for quite awhile. Not a bit deal except that it's a rather annoying sound during a supposedly relaxing bath!

So I guess we just have to be conscientious about switching the diverter toward the toward the tub after each shower.

Hopefully the problem is solved and the last two days haven't been flukes!

Dapoppa, don't worry; I had no intention of doing any major fiddling on my own unless the solution was easy and obvious. However, I have learned the hard way that unless a contractor has encountered the exact situation in the past, he--like pros in many professions--may start experimenting in a way that's likely to cause more problems. I like being an educated consumer.

Here is a link that might be useful: Dripping Bathtub Discussion

"So I guess we just have to be conscientious about switching the diverter toward the toward the tub after each shower. "

if I understand you correctly, your old system had the diverter in the tub spout. That type is held in place while in use by water pressure. Once the pressure stops, the diverter falls and all the water in the line drains out. Your new system requires you to open the diverter for the water to drain out.

My tub shower has been like this for over 40 years. Opening the diverter is something I do unconsciously whenever I turn off the water. Half way is better than all the way.

Exactly, weedmeister. Although we often did it manually in the old shower too, just to minimize the possibility of someone getting shot in the face from the shower when turning the water on for the first time! ;-)