I have a 3 handle system in our tub/shower combo. The problem is that when running bath water, the shower head will leak water. But the tub faucet does not leak water when the shower is running. I have replaced the diverter valve and it does not correct the problem. Both the hot and the cold valves appear to be fine. When all are turned off, there are no water leaks. What could be causing this and is there a way to correct it?

How old is this faucet? Could it have been installed upside down?

The plumbing in the walls is about 30 years old. The plumbing fixture for the spigot is about 8 years old. All the stems including the diverter are new this year. This problem was not occurring until about 1 year ago. We first tried replacing the seats and washers but it did not change the problem. We have lived in the house about 15 years and have replaced the stems before without any problems. Since the hot or the cold are not dripping when all is cut off, we thought the diverter might be the problem. It is puzzling though that it only seems to have a diverter problem when the tub water is running not when the shower water running.

Change the seat

We changed them when we replaced the stems and diverter.

It makes me wonder if any debris got past the diverter and into the pipes going to the spout.

I removed the diverter valve and seat from the fixture. Then used a3/4"dia. Wire brush and cleaned the inside of the fixture then purged with water to clear out the debris.Put it back together and its working just fine.Thank you for your help.