Plumbing flow and pressure problems in a new house

[Groundswell]

I'm a contractor who just built a brand new home. It has all new water supply piping, all new fixtures. It's a 3.5 bath house with one kitchen, one laundry room. There's a 3/4" meter at the street. There is 59 PSI of pressure at the meter coming into the house.

We are experiencing a dramatic reduction in pressure and flow to the two upstairs bathrooms, especially when more than one fixture is running at time. We're losing about 15 PSI of pressure in less than 20 vertical feet of rise between the basement where the water comes in and the second floor bathrooms. Our plumber swears that every pipe is sized according to standard residential plumbing best practices.

What would be the best way to troubleshoot the pressure and flow problems? We need to be able to have multiple showers and a washing machine or kitchen sink running at the same time and still maintain decent pressure. What would you do to improve this? Would a booster pump be a solution? Would paying the city over $10K to come out and increase the meter size from 3/4" to 1" be the best path forward? Could it potentially be an obstruction somewhere in the system? Does it sound possible that our plumber is lying about having sized the pipes correctly? Would really appreciate your expertise and feedback!

 

[Reach4]

The hose bibs on the house should tee off before any cartridge filter or backwashing filter or softener.

I suggest you get maybe 3 garden hose thread pressure gauges. See what the pressure is on the first outdoor spigot to tee off. Maybe try a second at a laundry tap inside, or put it on the drain valve for the water heater.. Keep one in reserve... (or just buy two initially). Turn on the tub full cold. That is probably your biggest flow maker. Watch for pressure drops outdoors and at the inside gauge while you are using a lot of water.

Some tankless WHs can restrict flow. That would be for hot water.

You can take a movie of a gauge with your cellphone if you don't have a helper to call out or record pressures.

20 ft of altitude corresponds to a static pressure difference of 8.67 psi. Then dynamic (friction) losses add to what you read.

Is the pipe thru the yard 70 ft of 1.25 inch CTS polyethylene or what??

 

[Sponsor]

 

[Storm rider]

Pressure and flow (volume) are two different problems. Is your problem pressure, volume, or both?

Was the house plumbed with copper or pex?

 

[Jeff H Young]

Sure its possible the plumbers a liar. its also possible your info isnt factual. could be obstruction all the way out at meter could be squiished if its poly pipe underground . gravel lodged a gate valve not all the way open .
So if 2 toilets flush in the house they barely refill? kitchen sink and a upstair shower no good running both at once?

 

[James Henry]

I would first ask the plumber to see his sizing calculations on paper and show you in the code book tables how he came up with them. That is where I would start or you will be chasing your tail.

 

[Jeff H Young]

I would first ask the plumber to see his sizing calculations on paper and show you in the code book tables how he came up with them. That is where I would start or you will be chasing your tail.

Not a Bad Idea Id do that no problem for customer.

 

[John Gayewski]

Is your pipe coming off of the meter 1"?

 

[Jeff H Young]

Awaiting Further info from Ground swell the Building Contractor. Ill go out on a limb and say I dont think its a case of a 3/4 meter being undersized and causing the problem. unless its like a 500 ft run and the main is undersized I think something else is going on. None the less details matter and until she comes back with at least some info cant really help. its too early to call the plumber a liar though.