Looking at a house to buy.  Seller says water supply is PEX (crossed-link poly?)   I guess the stuff is relatively new to the market?  Don't know much about it.  Is that stuff OK?  Or is it better?

Also, water input pressure is 88 psi.  Inspector says to install a pressure reducer and then an expansion tank at the water heater to avoid premature water heater failure.  Big deal or not?  Water heater happens to be in the attic.

Is it on a well? If so, needs an adjustment down on the pressure switch. City water usually runs at less than half that.

I rank copper first then pex then pvc.

In my opinion 60 psi is optimum.  Inspector is right.  Pressure reducers are fairly inexpensive.

Yeah, mine (well) is on at 40, off at 60.

No well.  City water - reading was taken at 10 AM, probably a high point during the day.

It depends on what city you're talking about. We have pressures from that can be in the neighborhood of 60-80psi around here.

They keep it in the neighborhood of around 40 here. A little higher would be nice, but 88?

DFW area - Lewisville

I've seen it that high in a small city just north of here. I was a licensed irrigator about a decade ago and it sure made sprinklers spray nice.

I'm just north of you - Sherman

I'm no plumber so take this with a grain of salt.

PEX is good stuff, If its crimped properly. Just keep in mind 1" pex has about the same flow as 3/4" copper, And 3/4 pex is the same flow as 1/2 copper. Many forget this. The OD is the same but because its plastic its thicker. Wiersbro may be different.
PEX is not new, maybe to you. I prefer to use pex, materials are more expensive but saves a ton on labor, especially fixing a leak!

I wish my house had 88psi !!!!
Pressure reducer is nonsense IMHO, But I like to actually get WET when I shower.
And yes I have all the damn flow restricters removed from the shower heads.


An expansion tank on a water heater is a good idea with any(tank style) water heater.
Just keep in mind they loose pressure after a few years and you should probably check if they need air, or they do no good.

If you're on city water, look above the MAin Water Shut Off valve inside your house.


you don't have a pressure valve about 2 feet above the Shut Off, inline?











Been a while since I lived in a neighborhood that didn't have 'em.



ETA: Home Depot sells a gauge you screw onto a faucet or hose bibb.  Turn on the faucet for 24 hours, it'll tell you current and highest pressure in the 24 hours.

Cost about $6.

Pex is great stuff.  
88# is ok. That's about what it is here in Minneapolis.

We did a 32 story highrise in Denver.   The risers were copper, but each unit was PEX (Wirsbo brand) off manifolds.   At the time of our training, they said that it has been used in Europe for 30+ years.   From a liability standpoint, I guess someone trusts it.

I just fixed a house in the mountains.  Foreclosure.  Water on, heat off.    The 1" copper burst, the shower valve busted open, and a gooseneck on a faucet cracked.   But the PEX lines were fine.

Most places, 80lbs psi is code.   Anything over requires the PRV.   The Home Depot gauge is a good idea, but there's one with a black and red needle, costs about $12.   The red one shows the max pressure over time.   Your peak pressure is actually more likely in the early morning hours, when demand is lower.

Thanks guys.  I'm going to have the seller install the pressure reducer and expansion tank.   Inspector said it can't hurt Said he had seen one case where 4 water heaters over 20 years were replaced and it was attributed to excessive pressure.  The knowledge of that guy from AC to plumbing, roofing, electrical and overall structure was amazing.

Thats great to hear, not many out there these days.  btw, have been using pex for 15 years an not one problem.