I'm working on a repiping project mainly to remove 3/4" copper cold water supply lines that run through my basement floor immediately after leaving the water meter (in a pit in the basement floor). I have suspicion that these pipes are leaking (20 degree colder spot in floor where the 3 branches tee off the main supply line & water meter spinning slightly with nothing drawing) and want to abandon them.

The street supply is 3/4" copper, feeding the meter in a pit as shown, which then continues from the meter with 3/4" copper buried in the concrete basement floor. Three branches tee off this main line to the Right, Left and Rear of the house, where they run up along the foundation walls with original (1948) gate valves.

The R/H branch off the main line is 1/2" copper, which currently feeds 3 separate pressure reducing valves for 3 hot water boilers, as well as 3 individual 40 gallon gas water heaters. As you can imagine, the hot water supplies have pretty low pressure... (It was originally intended for one steam boiler & one 80 gallon water heater - Not so anymore)

The L/H branch off the main line is 3/4" copper all the way, which feeds three bathrooms (tub/shower, sink, toilet) on 1st, 2nd, 3rd floors; three washing machines in basement, and a sillcock.

The Rear branch off the main line is 3/4" copper all the way, which feeds three kitchens (kitchen sinks only) on 1st, 2nd and 3rd floors, and a sillcock.

So my plan is to get the meter out of the pit if I can, run a new copper supply from the meter up the foundation wall and to the 1st floor joist level, transition to AquaPEX, and recreate the 3 branches described above, but making them all 3/4", and tie them in to the original 3/4" copper supply piping that runs up through the walls to each floor.

Would I get any advantage by running 1" copper from the outlet of the meter, and 1" AquaPEX all the way to where I will tie in to the existing 3/4" branches, even if my street supply is 3/4"?

I hope you guys can visualize this project a bit. Here are some pics of the meter pit (and nasty ball valve) that I'd like to abandon by running the main supply (3/4" or 1" ) up this wall adjacent to the ground wire:





So my main questions are, should I be sizing these new runs with 1" or 3/4." The layout I was planning on was: 3/4" line from the meter, teeing off a 1/2" line to the 3 boiler feeds, teeing off 3 separate 3/4" lines for each water heater inlet, a 3/4" tee off to the bathrooms/laundry (LH wall), and 3/4" to the kitchens (rear wall). Or should I be doing these runs with 1" and reducing to 3/4" when I transition from PEX to the original copper?

-Nick

first off, understand that I am partial to manifolds.
having said that, I would pipe from your main to the meter with 3/4 copper and from the meter to a multi-port manifold with 1 inch.
look around because they have them 1 inch manifold with 3/4 outlets with stops.
you would have to figure out which way to pipe the cold water but 7 outlets with 3/4 stops all set up for pex sounds about right.
3 for the water heaters
3 for the bathrooms
1 for the kitchens and boilers.

Have you considered that the city may NOT like you "moving" THEIR Water meter? Here, it is about a $10,000.00 fine for tampering with ANY utility's meter.

some do and some don't.
here they want to notified of the change, have the work done by a licensed plumber and then the DPW sends one of the boys down to make sure they like what was done.

I've thought of a manifold system, but I think the amount of piping in my situation would be excessive. I'm tight on joist bays (they're 12" O.C.) due to the piping for 3 heating systems, electrical, gas, telephone, cable, AND the fact that these pipes need to run over two beams, which are both fire-blocked with brick and mortar. I'd like to do a manifold setup, but I just don't have the room.

I'd also like to keep the existing 3/4" supply piping that's already existing and running through the walls to each floor. Running individual supplies to each floor would be a much larger undertaking.

I'll be doing the re-piping myself. The meter relocation itself, though, will be done by a licensed plumber. The meter location isn't a problem on it's face, but I figure it might be best to have it up and out of the pit, along with new ball valves isolating both sides of the meter, and a ball valve isolated drain valve if the house ever needs to be drained down in the future. Maybe even a pressure gauge in there too... I can do all of this with the meter in it's original place, though, so there's no problem if I decide to keep it in place.

-Nick

nick, if you want a ball valve and a drain above the meter, use one of these.
not really more money and it saves a step in labor.

Looks great to me, that should work well. Thanks Packy.

I had a little time to make this Isometric of my cold water system: