Rookie plumbing mistake? PEX to shower

[Sans1964]

Put in a new tub and shower faucet. Ran 3/4 PEX from 3/4 primary line hot and cold . I have bad pressure and flow. Should I have ran 1/2

 

[CountryBumkin]

You would not have any problem with 3/4. The difference between 1/2 and 3/4 is not going to effect pressure. Something else is wrong. Did the line get pinched/crimped somewhere? Do you have good pressure from other fixtures in the house?

 

[Sponsor]

 

[Reach4]

Put in a new tub and shower faucet. Ran 3/4 pex from 3/4 primary line hot and cold . I have bad pressure and flow. Should I have ran 1/2

You said that backwards, right?

 

[hj]

LARGER pipes do NOT cause less pressure and flow. You did something else incorrectly.

 

[Jadnashua]

While pex's ID is smaller than copper, 3/4" pex should be able to provide about 8gpm on the hot side and a bit more on the cold. Depending on how many showerheads you have, and the valve involved, that's usually more than enough. 1/2" pex will easily provide all of the flow and pressure needed for one showerhead, but might start to taper off with two depending on your setting on the hot water supply (i.e., how much cold you can mix in).