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 water pressure
Author: BucTX (TX)

Water pressure from city meter is 40 (not sure over the course of the day); they tested it once.
Right after the meter, we have a reducing valve. Near the house, I just intalled a backflow valve (city didn't have one). After the backflow valve, water line goes in 2 directions: into house and out to the outdoor faucets.

City (small town) has re-ocurring issues with water supply, hitting water lines, etc., thus concerned about debris.

When no water is running inside or outside of the house, outdoor faucet pressure is 40. However, when running a water faucet outside, there is zero water inside the house.

Jus the reverse When taking a shower; the outside faucet pressure is zero. When shower is turned off, pressure outside goes to 40.

Also, I had 2 new hot water heaters replaced a month ago because city has a water well station where big trucks fill up. One company had used a vacuum pump (weren't supposed to) and sucked all the water out of our lines and damaged both Hot W Heaters (both leaked in the house).

Also, when just 1 outside water faucet is on, the cold side of the hot water heater line gets hot, telling me that hot water is being sucked out of the H WH.

Clueless. Frustrated.
Any help would be appreciated.

Post Reply

 Re: water pressure
Author: steve (CA)

Is the 40 psi on the meter side or house side of the regulator? What material is the supply pipe between the meter and the house?

Post Reply

 Re: water pressure
Author: bernabeu (SC)

? What is the pressure INTO/BEFORE the 'regulator ?

? What is the flowing pressure AFTER the regulator ?

? What is the static pressure AFTER the regulator juuussst after you stop using water ?

? What type of 'backflow' valve do you have ? They can have LARGE normal pressure drops.

? What type of piping do you have ? What size ?

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Post Reply

 Re: water pressure
Author: packy (MA)

take out the pressure regulator. none needed if your pressure is 70 PSI of below.

add watts n36 vacuum relief valves at the water heaters. they will stop syphoning of water heaters should a zero pressue occur again.

it appears that your water main is either very undersized or clogged with rust/debris?

Post Reply

 Re: water pressure
Author: bernabeu (SC)

Quote

..... take out the pressure regulator. none needed if your pressure is 70 PSI of below. .....




none needed if the pressure INTO the regulator is 80 PSI or below


code states that the maximum allowed domestic water pressure is 80 psi (static) AT THE POINT OF USE (the fixtures)


ditto what packy said

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



Edited 1 times.

Post Reply

 Re: water pressure
Author: BucTX (TX)

Is the 40 psi on the meter side or house side of the regulator? City showed 40 psi at meter (going to house).

What material is the supply pipe between the meter and the house? 3/4" PEX B. About 50 feet from meter to mobile home. 3/4" pex going into the house.

Post Reply

 Re: water pressure
Author: BucTX (TX)

Appreciate everyone's time.

Our set-up: meter; 1 foot to pressure regulator; 50 feet to a newly installed backflow valve (which is right before line goes up to the mobile home. When line goes up, it "T's" (line to faucets and line to house).
I'm working on installing the faucet line on the other side of the backflow valve to prevent water from being sucked out of home when outdoor faucet is on.


bernabeu
? What is the pressure INTO/BEFORE the 'regulator ? Not sure what psi is, just before the meter. City measured 40 psi just after the meter (side going to the mobile home). The pressure reducer is within 1 foot of city meter and thus, I assume 40 psi going into pressure reducer. I have not disconnected regulator to test pressure after it.
Regulator is Watts LF25 AUB (25 to 75 psi)

? What is the flowing pressure AFTER the regulator ?
Not sure how to test flowing pressure (I just have a screw-on faucet gauge)

? What is the static pressure AFTER the regulator juuussst after you stop using water ?
I'll test this afternoon (at outdoor spigot) when no water is being used in the house (washing machine currently running).
However, when no water is in use (inside or outside), the pressure at an outside faucet is between 40-50 psi. However, when outdoor faucet (just 1) is turned on for 30 seconds, pressure at that faucet is reduced to less than 5 psi.
Also, when washing machine is running, it alarms (low or no water pressure) if an outdoor faucet is turned on.


? What type of 'backflow' valve do you have ? They can have LARGE normal pressure drops.
Backflow valve: I'll have to find the invoice. I can't see any markings on the one that was installed.
Reason there is one, is due to the city constantly having water issues. They have a water pump station just down the road from us, where large vacuum pump trucks/trailers suck water (vs. gravity flow like they are supposed to) and I have been afraid (especially it being a mobile home and because we've had 2 hot water heaters crack at the exact same time causing water damage [assuming from water being sucked out of them]).

? What type of piping do you have ? What size ?
3/4" PEX B from meter, to the mobile home (about 50 feet), and into the home.

Post Reply

 Re: water pressure
Author: BucTX (TX)

Author: packy
"...take out the pressure regulator. none needed if your pressure is 70 PSI of below."

My concern is a pressure spike due to City issues and it being a mobile home (if that makes any difference).

" ... add watts n36 vacuum relief valves at the water heaters. they will stop syphoning of water heaters should a zero pressue occur again."

*I'll have a plumber come do that. I've noticed, with outdoor water off, the cold side of the hot water heater still gets hot when washer is running and someone takes a shower.

*I considered having a plumber install backflow valves on each hot water heater but I'm not sure if they are ran in series/parallel or completely separate.

"...it appears that your water main is either very undersized or clogged with rust/debris?"

I "think" incoming line is 2". I ran 3/4" pex from meter into the house (which has 3/4" pex).



Edited 1 times.

Post Reply

 Re: water pressure
Author: steve (CA)

check the inlet of the regulator for a debris clogged screen. I would eliminate the regulator.

Post Reply

 Re: water pressure
Author: bernabeu (SC)

ditto



D'OH moment - debris clogged screen

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Post Reply

 Re: water pressure
Author: BucTX (TX)

Thanks for all the help.

With no regulator, what's the chances that a spike in water pressure bursting pipes in the house?

Post Reply

 Re: water pressure
Author: packy (MA)

the relief valve on the water heater would blow before any pipes burst

Post Reply

 Re: water pressure
Author: BucTX (TX)

I'll remove the PRegulator.

What about the backflow valve? I think I should leave it since there is a problem with main water being sucked out by vacuum trucks. It is installed just before the line goes up into the house (it then Tee's off to outdoor faucets).
QUESTION: should the outdoor faucet line be on the other side of the check valve (between main and check valve) or leave them where they are? I think leave them because if move them to the other side of the valve, when water is used outside, then the valve shuts off water to the house and if any water is used inside, it would drain the lines, correct?



Also, still think the watts n36 vacuum relief valve in the cold water line going to each of my HWH is needed? How do they not leak water?

Is an expansion tank needed at hot water heater or will the V. Rel. valve cure the problem of hot water coming back into the cold water supply line?



Edited 1 times.

Post Reply

 Re: water pressure
Author: steve (CA)

Yes, an expansion tank is needed if you have a backflow valve.

Post Reply

 Re: water pressure
Author: BucTX (TX)

If I install an expansion tank, is a vacuum relief valve still needed?

Potential issues with removing the backflow valve? It is there because of the risk of water being sucked out of the main by the city. However, these issues started when it was installed last month.


I'll get a plumber to install the expansion tanks, etc.
I can do plumbing (pex fittings, etc.) but not comfortable with inside lines.
Thanks,



Edited 1 times.

Post Reply

 Re: water pressure
Author: Curly (CA)

A typical backflow device will reduce water pressure approx. 12 psi.

A true backflow device comes with a rating plate(or stamped on body) that tells you brand, model number, serial number & pipe size.

You are feeding the whole system with a 3/4" pex line and 25 to 30 pounds of pressure.

Pipes to small and pressure is too low.

You answered your own question.....It all started when backflow was installed.....which reduced pressure.

Post pictures of your layout and maybe we can help.

Post Reply

 Re: water pressure
Author: BucTX (TX)

Post Reply

 Re: water pressure
Author: Curly (CA)

Maybe you should get a booster pump and pressure tank. I would think it should help smooth out your supply and not be depended on the city.

Hopefully somebody with more experience with pumps etc. will chime in.

Post Reply





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