When faucet is turned on in tub the pressure is great. When the shower is engaged the pressure decreases rapidly.. makes a gurgling sound and completely stops coming out. We have not had anything done to our bathroom, except that I took off the shower head to clean it of lime & rust build up, but that was about two weeks ago. Any ideas?:confused:

Take the shower head off and run the shower. Strong stream? If so replace the shower head. If not get back to me with the brand name of the valve. Regards, Tom