DEAR MIKE: I have a bathtub/shower combination, and when I pull the knob on top of the spout to start the shower, only a little water comes out of the shower head while most of it comes out of the tub spout. Do I have a clog in the pipe or is this a water pressure problem? -- Howard L.
DEAR HOWARD: Neither. You have a shower diverter problem. We've all been there; it's like trying to wash your hair with an eyedropper while your feet get saturated.
The tub spout you have with the knob on the end of it is a shower diverter. The knob diverts water away from the tub spout and up to the shower head. In your case, the diverter needs to be replaced.
This repair is easy and inexpensive. If all goes well, there will be plenty of water coming out of the shower head in about 30 minutes.
Since the diverter is built into the tub spout, you must replace the entire spout. There are a variety of colors and finishes available at the home center for about $15.
First, you need to remove the old spout, which fits on a copper pipe coming out of the wall. This copper pipe is usually one-half inch or three-quarters of an inch, and may or may not have threads on the end of it. Most newer homes do not have threads on the end of this pipe.
To remove the spout, look underneath it and see if there is a setscrew. If there is, use an Allen wrench and loosen the screw. You'll then be able to pull off the spout. If there is no setscrew, twist the spout counterclockwise (it will be attached by the threads on the copper pipe) and unscrew it like a lid off a jar.
Once you have a replacement, either screw it onto the threaded pipe, or push it back on the unthreaded pipe and lock it in place by tightening the setscrew. Check the instructions to make sure that the pipe is within the manufacturer's guidelines regarding length. If the pipe is too long, cut it to size with a pipe cutter and remove the burrs with the reaming tool on the pipe cutter.
Now turn on the water, pull up the diverter knob and relish the feeling of showering under a fire hose.