Out with the Galv. and in with the PEX. How to run new PEX?

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Dplang

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I have a 1938 home with galvanized cold water lines running through the basement. After seeing the plumber do two bathrooms in PEX, I think I'd like to have the galvanized replaced in PEX. I would like advice on how to run the new PEX. Should I follow a similar path as the original run, or mimic what the prior owner had done with the hot lines and make the runs around the perimeter? I'm open to other ideas, but cannot do any home runs because all of the spaces have been remodeled. I'd like the changes to be confined to the basement. A picture is attached of existing runs and two proposals. Thanks in advance for your help.
 

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Terry

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https://terrylove.com/watersize.htm

You have four toilets in the home. You're going to need something a lot bigger than 3/4 on the cold.

water-size-dplang.jpg


You need 1" from the meter and on at least some of the branch.
 

Dplang

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Meter.JPG
https://terrylove.com/watersize.htm

You have four toilets in the home. You're going to need something a lot bigger than 3/4 on the cold.

water-size-dplang.jpg


You need 1" from the meter and on at least some of the branch.

I would have never thought of that because of what was already there. Is there an issue if the meter is 3/4" (see attached photo of meter)? Besides that, it would be easy to run 1" for some of the trunk. Are there any issues with the runs I proposed? I'd prefer proposal 2. Thanks!
 
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Terry

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The chart is based on a 3/4" water meter.
Run 1" from the meter and break it down according to the chart. Keep in mind that PEX is a smaller ID than copper.
Friction loss is the big issue.
At my parents place, they had a 3/4" copper line that ran 250 feet. I replaced with 1-1/2" PVC (full size ID) and the difference was huge. I was able to use irrigation for their yard. With the 3/4" line that had proved to be impossible.
Using the chart, work the numbers backwards from the furthest fixture, increasing as needed as you head to the water meter.
Page 2 is fine if you change some of the line sizes.
 

Dplang

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Very helpful info. I've updated the drawing to reflect 1" PEX cold lines. Are there any other issues to consider? Will the 50 gal Kenmore water heater (7 years old) or any other fixture need any adjustments with a slightly larger ID and a higher flow?
 

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Jadnashua

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Other than adapting the input size to the WH, it won't need any other changes. Because you may now be able to get more gpm out of the thing, you may find you're using more hot water, and it runs out faster, but that's a personal thing! WH average about 7yrs. SOme can last much longer, some die sooner. You may be about ready for a new one.
 

Dplang

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Attached is my design for the entire run with all connections. Does anyone see a mistake or issues that should be corrected?
 

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Reach4

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If you may want to install a water softener at some point, you would probably want to feed unsoftened water to the hose bibs. If you plan a spot now, that could make the softener install better later.

I would also be considering a whole house water filter, even on city water. You would want one that can handle the max flow with some margin, since the ratings would normally be for when the cartridge is new.

You understand that the coupling to the water meter is going need a water meter coupling rather than NPT.
 
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Dplang

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If you may want to install a water softener at some point, you would probably want to feed unsoftened water to the hose bibs. If you plan a spot now, that could make the softener install better later.

I would also be considering a whole house water filter, even on city water. You would want one that can handle the max flow with some margin, since the ratings would normally be for when the cartridge is new.

You understand that the coupling to the water meter is going need a water meter coupling rather than NPT.


Interesting point about the meter connection (see picture above from prior post). I was told that the connection to the meter will go below the galvanized T, which will be removed. Is there a code or best practice that requires a different approach? Thanks for pointing that out and the water softener comment.
 

Reach4

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Interesting point about the meter connection (see picture above from prior post). I was told that the connection to the meter will go below the galvanized T, which will be removed.
Ahh... so that brass going to the tee. Nice. That makes sense.
 
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