A: I may have some good news and some bad news for you. The problem you describe is usually a diverter valve issue. The diverter valve diverts the water from the tub spout to the shower. Some diverter valves are located in the main mixing valve assembly and some diverters are located in the tub spout itself, where you pull a lever.

The good news is that this is usually a simple job for a plumber to fix and the wall should not have to be touched. The bad news is that since your husband did not know of the diverter and was ready to open up the wall, he may not have the experience to tackle this project without some help.

The job will include trouble-shooting the type of diverter in your tub/shower, locating and picking up the correct replacement parts, and installing those parts according to the manufacturer's directions.

I suggest your husband work with your plumber on this one. If he learns from this job, he can try future diverter repairs. Please note that diverters can fail from time to time -- and even when they're working correctly, for safety reasons a little stream of water may drain from the tub spout when the shower is on.