Low water pressure unless sink is on

[mlancaster]

We installed a new shallow well jet pump this past weekend and it took awhile to get it primed and running. Ever since in our upstairs bathroom, the shower and toilet get barely a trickle of water unless I turn on both the hot and cold side of the sink. I checked the cartridge in the shower handle (single handle delta, 14 series) and it rattled when I shook it so it seems to be in working order. What else could be causing this to happen?

 

[Reach4]

During the problem, what does the pressure gauge indicate? If under 30 psi, consider cleaning the jet.

 

[Sponsor]

 

[mlancaster]

We actually got it fixed! We had a couple small leaks in the pipe leading from our pump/tank setup that must’ve happened when we swapped the pump. We fixed them up yesterday and now the shower pressure is noticeably increased without having to run the faucet lol thank you for your suggestions though!!