View Full Version : Water Pressure

12-14-2008, 06:42 PM
After constant manipulation with my watts pressure reducer, my water pressure is at 80 - 90psi which my family can barely handle. This is the reading I notice every morning before anyone wakes up.

I understand that normal water pressure is about 60 - 70 psi but when I had my water pressure at 60 - 70 psi when reading it first thing in the morning, we could not shower comfortably, two showers cannot run at the same time or a shower with a running faucet with a toilet flush was even horrible. I hope you get the picture.

How can the majority of homes run at 60 - 70psi and be bearable with everyone living in that home? Is there something wrong in my house?

12-14-2008, 07:07 PM
Sounds like you have a resrtiction of some sort or, a faulty PRV.

12-14-2008, 07:15 PM
What can I do to test to make sure?

If I need a new one, can i just get the same size at home depot. I have a 3/4 prv. Will it help if I get a bigger one?

Gary Swart
12-14-2008, 08:29 PM
What kind of pipes is your house plumbed with? If it is an older home with galvanized pipes, it is likely the inside of the pipes are corroded so you can not get enough water through. Keep in mind that pressure and flow are two separate things. If the pipes are copper, then your PRV may be faulty. It could be partly clogged or defective. If you need a new PRV, size it to the same as your incoming water supply line.

12-14-2008, 08:53 PM
Seriously, I am not suggesting that anyone do any plumbing without the direct guidance of an experienced, knowledgeable, honest, Professional Plumber (((preferably one that has both SERVICE & CONSTRUCTION experience))) . - . - . [ such as ( (ahemmmm ... lol)) Myself ]

having that plumber stand beside you at the time of the repair is always a beneficial idea :) and that simple procedure shall often save you from a lot of this :eek::mad::confused:

IF ... you . . . ( can I circle the word IF ? )

IF ... you Replace a pressure-reduction valve, use the same size unless your needs for available psi have increased. The original 3/4" size you mentioned is suitable, many times, for single-story 1-2 bathroom homes with mild to moderate water demands and therefore is "perhaps" the perfect size for your home.

<<< please, do NOT attempt any plumbing project if you are not certain that you are aware of what CAN Go Wrong on a plumbing project, and what steps to correct the trouble if upon your 1st attempt, you are not successful. You mustn't attempt any plumbing unless you can cross THAT hurdle ( Service Plumber knowledge & experiences ) >>>

Perhaps you have a faulty valve ( or just OLD ) and need to replace it. Or you may indeed be experiencing a restriction or fault someplace within your home's piping.

And I am not suggesting that anyone do any plumbing without the direct guidance of an experienced, knowledgeable, honest, Professional Plumber [ such as ( (ahemmmm ... lol)) Myself ]

However, let's remember that most times, on a PRV, turning the adjustment screw so that it threads itself out away, causes the available pressure to be increased toward the maximum limits of your New PRV.

Water supply piping:
Most cases, 3/4 inch - - @ 50 to 60 psi is most comfortable
Most cases, 1" to 1 1/4" @ 60 to 75 psi is sufficient for 2 to 3 story buildings, or high demand plumbing fixtures installed throughout a large sprawling custom home ( custom bath features and spa, multiple shower heads, 4 or more bathrooms, etc., for instance )

My . S T R O N G E S T . suggestion is that anyone seeking to make their plumbing work properly ... please ... seek out professional assistance, unless you ARE that person ... the expert.

12-14-2008, 09:16 PM
OHHHH, Don't Forget about MAX pressure

most insurance and warranties become invalid if your water pressure is above 80 psi ( in many municipalities of America )

12-14-2008, 09:19 PM
I do have copper piping in the house.

It looks like my copper pipes inside the house is 1/2 inch. Does that play a factor in choosing the prv fitting? Will my pressure help if I increase the prv to a 1 inch fitting.

Just so I understand how a prv works. If the prv is working properly and set to 60psi, should the the water pressure stay at 60 psi even when a facuet or shower is opened?

Gary Swart
12-15-2008, 12:52 AM
I don't understand what this statement means: "Does that play a factor in choosing the prv fitting? Will my pressure help if I increase the prv to a 1 inch fitting?" As for your last question, pressure should remain constant at the pressure set in the PRV. It is my opinion that your PRV is either defective or needs cleaning as previously described. Your expansion tank should also be checked to make sure it is working and replaced if it is not, but that should not affect your immediate problem.

12-15-2008, 04:55 AM
Would it help if Mikey did some kind of quick check of water flow - say time how long it takes to fill a 5-gal bucket?

Sounds to me like there is a restriction somewhere in the system.

12-15-2008, 06:54 AM
Possibly even a clogged screen on a PRV.
The 2 different postings make this a bit confusing!

12-15-2008, 07:39 AM
Sorry for the double posting but I thought they were two different issues.

Since the problem seems to be with the prv, I'll replace it with a new one from Home Depot.

Based on what I understand, you unscrew the old prv, put in the new one place and screw it tight. Is that all?

Btw, the expansion tank was replaced just about a month ago.

WV Hillbilly
12-15-2008, 07:42 AM
If your whole house is plumbed with 1/2 inch pipe your problem could be lack of volume instead of lack of pressure . ( I THINK ) If I'm wrong someone will straighten me out right quick .

12-15-2008, 08:34 AM
A residential regulator will adjust to a MAXIMUM setting of 75 PSI so your regulator is bad. Failed regulators often exhibit TWO symptoms....high static pressure AND low dynamic pressure. Have you tried checking the pressure when you have a faucet running. From your description, we can guess that it will read low. Need a new PRV.

12-15-2008, 08:42 AM
The pressure is about 20 psi when a faucet is running.

I know a new prv is pre-set at 50 psi. Is it OK to set it to the max 75psi from the very beginning?

12-15-2008, 11:54 AM
Check the flow you get at the factory pressure setting.
If it was the problem you probably will find it acceptable.

12-15-2008, 06:00 PM
I have a shut off valve before the water meter but none after the prv. Just so I get this correct, I should close the valve before the meter, close both cold and hot valves on the water heater and open a faucet to release all the pressure in the pipes. I'm just afraid once I remove the prv, water may flow backwards since there is no shut off valve after the prv.

Is this correct?

12-15-2008, 06:59 PM
I would just close the main valve open a faucet at the lowest point to drain off the pressure then place a bucket under the prv and start removing it.

12-15-2008, 07:14 PM
Just like your thumb on a straw, most of the water will stay in the pipes, but a little will come out if you open a valve. I'd shut the main off, open a valve to relieve what little pressure there is (with an expansion tank, you'll have some stored in it under pressure), then when the flow stops, consider closing that valve again, then taking the PRV out. You'll get a little come out, but with a bucket there, and the pressure relieved, it shouldn't be a huge amount. Now, it's not uncommon for the main shutoff to leak, so that could be a problem...just be fast!

12-16-2008, 05:22 AM
Saying, "you turn off the water, remove the PRV, and install the new one" reduces the process to its lowest terms. The reality is that it could become a bigger job if the new one is a different length than the old one, which is most likely, or it has differnt connections.

12-16-2008, 06:55 AM
I knew it was too good to be true! :D :p