Reply To: Adding Shower over tub

The faucet connects to the top front opening, but the port in the twin elbow is much smaller than the pipe entering it. The shower goes up the rear top opening, and the 3/4 spout connects to the front. When you turn on the faucet, the twin ells smaller opening limits the water flow to the amount that the spout can handle so there is no back pressure to force water up the showerriser. When you operate the diverter spout, then the water is forced up the riser and out the head. Using elbows and tees will not reduce the flow and the water will exit the shower head every time the faucet is turned on with any force. In certain cases, you may have to use the top rear hole for the faucet and the other one for e shower. In most cases that will work properly.How does a twin elbow work?