water pressure reaches 140psi

Users who are viewing this thread

diybasement

New Member
Messages
3
Reaction score
0
Points
0
Location
Georgia
I put in a new pressure reducing valve because the old on was going bad (2 weeks ago). When the water is being used during the day, it stays between 50 and 60psi. I left my pressure gauge on the supply line over a couple of days and at some point it reached 140 psi. On the cold water side, I have an expansion tank set at 52 psi. The water company put a new meter outside two months ago. The outside pressure is 140psi. The pressure reducing value is factory set to 50psi

1) Could the new pressure release valve be bad?
2) Could my expansion tank be bad? It is reading 52 psi
3) Should I put an expansion tank on the hot side too?
4) Should I put another pressure release value after the current one that is in.

Thanks for your input.
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
1) You have a pressure release valve and an expansion tank?
2) Could be. Even if it is good, you should set the precharge to 60.
3) I don't think so.
4) It's a valve... You have a pressure relief valve? Are you referring to the valve on the water heater?
 

diybasement

New Member
Messages
3
Reaction score
0
Points
0
Location
Georgia
My bad. I should have said pressure reducing value for all my questions.

1) Could the new pressure reducing valve be bad?
2) Could my expansion tank be bad? It is reading 52 psi
3) Should I put an expansion tank on the hot side too?
4) Should I put another pressure reducing value after the current (pressure reducing valve) one that is in.
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
1) pressure regulator could be bad, or expansion tank could be bad.
2) Could be. Even if it is good, you should set the precharge to 60.
3) I don't think so. They do have devices that release water if pressure gets to 70 or 80.
4) You should not have to.
 

Jadnashua

Retired Defense Industry Engineer xxx
Messages
32,770
Reaction score
1,190
Points
113
Location
New England
This may be obvious to you, but where is the expansion tank? It is supposed to be on the cold inlet to the WH after the shutoff valve so that it is always there to be able to absorb the expanding water. IOW, there should be no valve between it and the WH.

Thermal expansion can easily raise the pressure to 140psi and above. It may be peaking at 140psi because something in the house is leaking - a common one is a toilet fill valve, and that normally won't show, since it just goes down the drain. All it takes is a bit of a drip somewhere. IF there is no leak, and the PRV is working, the T&P on the WH is the next most likely thing to release (or leak).

So, the expansion tank could be bad, or the PRV could be bad, or the expansion tank is not installed properly.
 

Wallijonn

Member
Messages
335
Reaction score
15
Points
18
Location
Arizona
I left my pressure gauge on the supply line over a couple of days and at some point it reached 140 psi.

I'm guessing that it happened when you used your clothes washer. I think the dishwasher only uses cold water. When not using the clothes washer you probably want both water valves to be closed. If the faucets aren't closed then the clothes washer mixing valve may be crossing hot water to the cold water side or cold water to the hot water side. If the clothes waser faucet outlet is 3/4" and you install 1/2" connecting flexible water hoses the decreased diameter should increase your water pressure.

Same thing applies to jacuzzis. Somewhere an appliance is causing pressure to build up. Or you have a crushed pipe somewhere in the house that causes the water pressure to increase and whatever is at the end of that pipe run may be pushing hot water back through the cold water pipe. If it is a mxing vale you'll have to test the kitchen faucet in all positions of cold and hot while having someone watch the water pressure meter. Hopefully you don't have a mineral clogged pipe somewhere.

It's all speculation on my part as I am not a plumber.
 

Stuff

Well-Known Member
Messages
1,221
Reaction score
130
Points
63
Location
Pennsylvania
Since speculation is allowed - Could you be measuring the peak water hammer?
 

Gary Swart

In the Trades
Messages
8,101
Reaction score
84
Points
48
Location
Yakima, WA
I think the dishwasher only uses cold water.

You haven't a clue about dishwashers. DW use only hot water. There is only one water connection and that is hot water.

On the original question, check the expansion tank by tapping it. If it's bad, it will be full of water and the sound will be a dull thud. A pressure gauge with a tattle tale needle will help you check the PRV. The expansion tank should be pressurized to equal the PRV setting.
 

Wallijonn

Member
Messages
335
Reaction score
15
Points
18
Location
Arizona
Nope, I don't have a clue because I never use them. Single, so it would take a week's worth of dishes & utensiles to make it worthwhile to use the dish washer. We have very high electricity rates. (4 to 5 times what I was paying in PA.) I also don't have a clothes dryer. When it's 110 outside it doesn't make sense to use a dryer, since it creates heat which the aire conditioner has to overcome - it's much easier to put up a clothes line up in the back yard. ymmv. And in the wintertime it hits about 50 degrees, so it'll take about 4 - 5 hours to dry instead of 20 minutes to 1 hour. Depends on the neighbourhood, though. Some who put their clothes on clotheslines get stiff clothes when they dry. My dishwasher is black, the sink is black, the stove was black, the refrigerator was black, the microwave was black. Galley kitchen. Dark brown cabinets. Very depressing. The sink can wait, the dishwasher I'm thinking of throwing out and installing a wine bottle chiller, and everything else has been changed.
 
Last edited:
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks