Water line sizing

[HBM]

I just had a 5 bed/bathroom two story plus basement home built and have a question about my water line size. Originally they installed a 1 inch poly line which was damaged.....after the fact I realized they replaced it with a 3/4 in line (and of course my builder/excavator both assured me it was fine) PSI at the main is around 120. Distance from the main to meter is 35 feet and distance to the house from the meter is 150 feet (house is downhill about 10 feet in elevation). 2 feet after entering the home it converts to a 1 inch regulating valve with 1 inch PEX trunks for about 10 feet In the basement ceiling which then goes to 3/4 inch another 30 feet in each direction. I have the PRV set at 70 psi in the basement.

I notice pressure issues mainly if 3 showers are running at the same time or 3 hose bibs are running sprinklers. (This doesn't happen much but my wife has mentioned pressure fluctuations while showering).

One or two showers at a time are fine which is why I don't think it would be worth digging my yard up at this point.

Is there anything I can so inside the house to improve this problem? Extend the trunk lines to 1 inch? Extend 1 inch lines all the way to the water heater?

 

[Sylvan]

Your have volume issues for sure. Hopefully you have anti scald type shower body's

 

[Sponsor]

 

[Terry]

Your home is about 43 fixture units.
I normally would have used a 1-1/2" poly or PVC line for that amount of volume needed and the the distance. PEX would be 1-1/2".

Maybe adding a good sized expansion tank would help at this point.

Just an example. My parents place was 250 feet from the meter to the house. The irrigation system I installed wouldn't work with the original 3/4" from the street meter. By changing the line to 1.5" PVC, the irrigation system worked fine. The heads that wouldn't pop up were now spraying a good amount of water in each zone. Same meter, different sizing on the line.

3/4" would be too small for a one bath home and you have five?

 

[Reach4]

If you had pressure gauges before and after the PRV, that could be useful in seeing where the pressure drop is occurring.

A bigger PRV could be called for. A bigger service line could be called for.

 

[HBM]

I can adjust the PRV to get a PSI up to 90-100ish. It is a 1 inch Zurn 1-600XL

Where would the expansion tank go? After the PRV, before the water softener? Any link to them?

Thank you guys for the reply

 

[FullySprinklered]

Use two PRVs, one for each direction at the split.

 

[HBM]

Fullysprinklered,

Sounds like a good idea to maximize the 120 psi from the main. Do you think doing the split to hot and cold would be better for all the showers?

 

[HBM]

Also I'm not sure my water softener would handle 120 psi which may pose a problem

Code only allows 80 PSI

 

[Terry]

Most codes only allow up to 80 PSI.

So the builder never pulled any permits for this job. You're kind of getting screwed on this. Too bad. The cost difference to have done it right was very little. Now you're screwed.

 

[Reach4]

Maybe have a regulator (PRV) for the softener, another for all other indoor use, and no regulator for the outdoors. If you do any plumbing changes add provisions for pressure gauges to know what is going on. A boiler drain valve is useful for water sampling and for mounting a GHT pressure gauge.

I am not a pro.

 

[Jadziedzic]

Was the incoming water line downsized with your permission? (No.) Since the answer is no, perhaps it is time to have a talk with the builder and have them fix their "mistake". If they're reluctant to do so a chat with your local Authority Having Jurisdiction might help, given the replacement is not sized properly.

This mistake will likely nag you the entire time you spend in your new house.

 

[OLD TIMER]

Was the incoming water line downsized with your permission? (No.) Since the answer is no, perhaps it is time to have a talk with the builder and have them fix their "mistake". If they're reluctant to do so a chat with your local Authority Having Jurisdiction might help, given the replacement is not sized properly.

This mistake will likely nag you the entire time you spend in your new house.

Yea, that's what I would do.