Hey guys i need some senior advice. I changed out a tub and shower valve for one of our builders in a old house (galvanized lines). I switched the two handle valve out to a pressure balanced valve and integral diverter(Plumbtrim made by brasstech) now seems to work perfect till you have the diverter on and the shower going. Then when any other fixtures get used the diverter pops and goes to the tub. I checked the psi to the house and it is at 52psi at the front hosebib and when i turn on the back hb i loose 5psi on the gauge. This might not help you help me but trying to let you know all the things i checked. I figure theres not enough backpressure between the shower head and the diverter when this happens. If i reduce the flow rate of the shower head do you think this will help !!!!! how do you tell the homeowner??????