Welcome to Plbg.com
Thank you to all the plumbing professionals who offer their advice and expertise

Over 680,000 strictly plumbing related posts

Welcome to Plbg.com the PlumbingForum.com. We are the best online (strictly) PLUMBING advice, help, dyi, educational, and informational plumbing forum. Questions and discussions about toilets, sinks, faucets, drainage, venting, water heating, showers, pumps, water quality, and other exclusively PLUMBING related issues. Please refrain from asking where to purchase a product, or any business, pricing, or legal questions, or for contractor referrals, or any other questions not related to plumbing. Keep all posts positive and absolutely no advertising. Our site is completely free, without ads or pop-ups. We do not sell your information. We are made possible by:  

Post New
Search
Log In
How to Show Images
Newest Subjects
 House water pressure drop
Author: yonson (SC)

Hi folks. In sc here. Public water. No expansion tank on my water heater. When I turn on a faucet the water pressure drop after about a second. No other fixture is open. Happens all the time. How do I retain the water pressure at my fixtures from the time I open them until I close them? Happens in all fixtures.

Post Reply

 Re: House water pressure drop
Author: packy (MA)

when you say "all fixtures" do you mean toilets, showers and outside faucets?

Post Reply

 Re: House water pressure drop
Author: hj (AZ)

usually, it is caused by a defective pressure reducing valve in the system

Post Reply

 Re: House water pressure drop
Author: yonson (SC)

Yes. Everything.

Post Reply

 Re: House water pressure drop
Author: yonson (SC)

I will have to Look for one tomorrow. No regulator in the house. If there
Is one out in the street key pit - who is responsible to
Replace it?

Post Reply

 Re: House water pressure drop
Author: steve (CA)

Has the main shut-off valve been checked, to see if it's fully open? What type of valve is the main water shut-off? If a gate valve, maybe it's broken.

Post Reply

 Re: House water pressure drop
Author: yonson (SC)

Would installing a pressure expansion tank help keep this water pressure consistent? I do not
Have one over my water heater.

Post Reply

 Re: House water pressure drop
Author: vic (CA)

It might help you sometimes and seeing less of an initial drop for at least 1 of 2 reasons:

Most likely you have a check valve in your line and so what might be happening is that most public pressures rise and fall and are not perfectly static at one pressure level and so when you're not running your water and not being used there might be more pressure in your static line at the time that you turn on your water which is coming from your public source. An example might be that your public source might fluctuate anywhere from 50-75 pounds. IF you have a check valve inline and aren't running the water .... at some time your line will be holding the highest 75 pounds of pressure and when you turn on your water that 75 psi will come out of your faucet initially and then go to whatever the current source's pressure might be such as 60 pounds.

Also as your water is heating if you have a check line in your line someplace feeding the water heater (such as at the meter or a pressure regulator) your pressure will rise in your house water line and that is the main reason for an expansion tank to take on (absorb) the extra expansion.

Post Reply

 Re: House water pressure drop
Author: yonson (SC)

So as a follow up. I installed a 2 gallon expansion tank on the cold side of my water heater. I left it at factory pressure of 25 psi. The problem has been eliminated. I now turn on a fixture and the pressure seems to stay consistent. Thanks all for you wisdom!

Post Reply





Please note:
  • Inappropriate messages or blatant advertising will be deleted. We cannot be held responsible for bad or inadequate advice.
  • Plbg.com has no control over external content that may be linked to from messages posted here. Please follow external links with caution.
  • Plbg.com is strictly for the exchange of plumbing related advice and NOT to ask about pricing/costs, nor where to find a product (try Google), nor how to operate or promote a business, nor for ethics (law) and the like questions.
  • Plbg.com is also not a place to ask radiant heating (try HeatingHelp.com), electrical or even general construction type questions. We are exclusively for plumbing questions.

Search for plumbing parts on our sponsor's site:




Special thanks to our sponsor:
PlumbingSupply.com


Copyright© 2022 Plbg.com. All Rights Reserved.