I am starting to realize that the answer to many plumbing questions is: "It depends."

Time has come to replace the 45 yo galvanzied supply lines that run through my house.

I am on city water and the meter is at the street which is about 35' from where it enters my house through the foundation wall. My house also sits down from the meter not a big drop but all but the upstairs shower head sits at or below the meter level. The meter is 3/4" and there is a 35' run of 3/4" PE(which is in good shape) from the meter to the house. The pressure at the meter is ~55-60 psi.

I currently have 23.5 fixture units but on the repipe would like to add a laundry room sink so would end up with 25.5.

The distance to the hot water heater from where it enters the house is about 60' so a total of about 95' from the meter to the hot water heater. The hot water heater is at the end of the line. All cold water branches off before it get to the hot water heater. The hot water travels back about another 25' to the last fixture.

My question has to do with what size pipe to run from the 3/4" PE to the water heater? I am going to use copper but in my reading a 3/4" pipe from the PE to the water heater, meaning 3/4" all the way from the meter,
can only adequately supply about 19 fuxture units?

Would running a 1" line from the 3/4" PE to water heater be a good idea? Not a good idea? not really make any difference? Have I given enough info to answer this question?

I appreciate any help here and hope my question is clear.

 

Your still sucking water through a straw. I'd go with larger if I had an idea of replacing the PE in a few years or less. Cost on piping between sizes not that great, labor is still the same. So it's not really a price thing.

It really depends.....

 

notuboo,
Thanks for your answer....


I hate to be redundant but I'm not sure I understand. Please bear with me.

Meaning that the 3/4" PE is the limiting factor??

Is it the length of the pipe?

Isn't the 3/4" meter also a limiting factor? I guess I get confused when I read about using a 1" or even 1 1/4" line from a 3/4" meter. Showing my ignorance of water flow characteristics. It would just seem to me that if you have a 3/4" meter that would be limiting to anything after it ? Or is the flow through the meter NOT a factor somehow?

So this 1" pipe would only help my flow if I also replace the pipe before it?

Thanks for the help.

 

Everything matters. It is true that the meter and the 3/4 pipe limit you. Distance is also a big enemy. What you can do to minimize any FURTHER loss is use a larger pipe size for the new run.

 

Thank You!

Should I step down to 3/4 before the hot water heater or 1" all the way with a reducer?

 

ill make it easy for you make your main run 1in1/4 then tee off to 3/4 to your unit this why your main pipe will be big for future use as well









get it done
lenny