New tub spout drips after turning off.
We just had a new shower/tub combo installed. It's a Hansgrohe handshower running into the wall with a separate tub spout, and a pressure balanced valve. When we run the tub the water continues to drip from the spout for about 1/2 an hour to an hour after we shut it off. Then it stops. Any ideas before we call our contractor? Thanks.