PRV/100psi/Hot Water Heater

[diyhah]

100 PSI, has been for 30 plus years. Should a PRV be installed for the irrigation system and for the house, one for both?
Reliance 501 52 gallon water heater installed in summer of 1992; no expansion tank. Has supported a family for 10 years and now a retired couple with a "clean freak" member. It is still working just fine, always has worked just fine.
Do we really fix something that does not obviously appear to be broken? Probably jinxing us with this post.

 

[Master Plumber Mark]

100 psi is fairly high for the house... it does put a lot of stress on the fixtures..
for the irrigation system its not necessary at all..

you have done fine with the heater so far but its time is running short for sure...

installing a prv for your house is not a bad thing to do and crank it down to about
70 psi inside.....

murpheys law says to wait till the heater finally goes out then install both at the same time

 

[Sponsor]

 

[Slomoola]

100psi is too high. Normal is 40-60psi. That higher pressure can and will wear your pipes internally faster than a lower pressure will.

For irrigation, your nozzles will be misting a lot with all that pressure. Or make sure you have about 8-10 heads per zone.

Test with another pressure tester. See what you get.

 

[Fitter30]

Install a whole house prv you will need a expansion tank now all the expansion is going out to the water main.

 

[Slomoola]

Install a whole house prv you will need a expansion tank now all the expansion is going out to the water main.

Anyone confirm or not, if any water going back into your meter gives you a water usage credit? Does/can the meter run backwards?

And how much expansion water are we talking about? Most water heaters are set around 115F or so right? Not even close to boiling. I know water can still slightly expand if heated under 212F.

My area is billed on what is it 1,000 gallon or 10,000 gallon increments. So looking at the big pic, and expansion water going back into a meter is small potatoes. In OKC, we or at least my house doesn't have any expansion tanks. Don't know of any other houses with them either. What so you guys think?

 

[Fitter30]

50 gallon tank, 45° incoming, 120° out, 60 psi, 3.5 gallons of expansion. 1 cubic ft = 7.48 ga!lons
Watts PLT- 12ex tank

Expansion Tank Sizing Calculator (Potable)

Expansion Tank Sizing Calculator (Potable)

www.watts.com

 

[John Gayewski]

Meters with no check valve can run backward.

 

[GReynolds929]

Anyone confirm or not, if any water going back into your meter gives you a water usage credit? Does/can the meter run backwards?

And how much expansion water are we talking about? Most water heaters are set around 115F or so right? Not even close to boiling. I know water can still slightly expand if heated under 212F.

My area is billed on what is it 1,000 gallon or 10,000 gallon increments. So looking at the big pic, and expansion water going back into a meter is small potatoes. In OKC, we or at least my house doesn't have any expansion tanks. Don't know of any other houses with them either. What so you guys think?

Still need an expansion tank.

 

[Slomoola]

Still need an expansion tank.

For?

My house was built in 1977. Been in it since 2013. Had copper throughout till now. Recent full on PEX A repipe. Had 82psi of pressure.

Never seen or heard any whale like pressure blow offs opening the hot water taps. Was the pressure increasing on the hot side, would say so. Never checked it. I have no idea to be fair.

Asked my repipe plumber about an expansion tank. He said he hasn't seen any installed in our area. Highly doubt there are any check valves at the meter or anyplace in the house. My meter is wide open.

My hot water tank pressure safety valve has never blown. I have 2 hot water tanks BTW. Not seeing any over pressure conditions at all.

I don't see a need for one. I'm here to learn and can see why, they are recommended. They don't last what maybe 3-7 years?

That little bit of water that might be going back into the line is inconsequential. We are billed on 1,000 gal increments. You and I will never see any water loss or increase in water usage on our bills. The gradual heating would slowly return water into the main. Doubt it would even be captured by the meter. Could be totally wrong. Won't be the first time.