Water Line Size Question

Hi There,

Looking for some insight\help on some plumbing work I had done a few months ago.
I needed a Water Softener installed as well as a new hot water tank and used someone that was recommended to me.
The job was done and everything seemed to be fine other than a substantial loss in water volume, meaning if one fixture was open it seemed to have normal water pressure but as soon as a 2nd one was opened the pressure dropped substantially. Two showers running is just about impossible.
I thought that the issue lied with the Water Softener itself but there is a bypass valve which I have used to bypass the Water softener and pressure(volume) does not seem to be any better.
I believe now that the issue is that the connections that the plumber used were too small for our house. 2500sqft two story 3 full bath + 1 half bath(more details can be provided if needed). It seems to me that the main water line is ¾ and the connections that he used are ½. Is this able to be confirmed through the attached Picture? Can anyone let me know if this could\is causing my issue.
Should I have the plumber back to fix or find a new one? Not dying to shell out more $$ and not have it fix my problem. Any help would be greatly appreciated. Thanks in Advance

57Chewie

WIthout some reference point, it is difficult to tell what the pipe sizes are because the ones at the rear could be 3/4", but look like 1/2" because of parallax. I do know, however that a real "plumber" would NEVER have used thos "petcocks" for shutoff valves. They could be the first source of pressure loss.

It would be common to plumb a softener with 3/4" copper, but the I.D. of pex is smaller than copper, and the pex fittings introduce even more of a restriction. Between the piping and the valves that are there, I would not expect enough volume to any fixtures.

he did use Uponor at least for some of joints so those fittings are a bit larger. I am also not sure if a "plumber" would have switched from one type of connection to the other. Sort of a cobbled up mess.

To get around the same flow out of pex as 3/4" copper, you should probably use 1" pex. 1/2" pex is fine for a single item, unless it is a shower with multiple heads, and it might be marginal for filling a tub at max rate (verses other supply lines). Something like a toilet could get by with even 3/8", but anything in the 'main' line, like feeding the WH needs to be bigger than 1/2" pex. A manifold out of the WH could have multiple 1/2" lines, though, each feeding individual points of use.

Thanks for all of the responses. If I were to call in a new Plumber what should I be telling him to do?

57Chewie

The piping should be no smaller than 3/4", and the valves must be 3/4" full port ball valves. If the house is plumbed in PEX, the bypass should be the same size or larger than the incoming line. For more that one bath, the lines should all be 1".