# Correct pipe size on hot water heater



## Joe Tilghman (Jan 19, 2012)

Should the hot and cold water lines coming from the top of the water heater be both 3/4" if the pipe on the cold side is 1/2 can this reduce water pressure?


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## oh'mike (Sep 18, 2009)

They are typically 3/4" on both sides----a very small house might have 1/2" but I have never seen that.

Yes the water pressure will be affected.


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## joecaption (Nov 30, 2011)

It will lower the pressure as much as 25%. Huge diffearance in volume between 1/2 and 3/4".


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## how (Feb 26, 2011)

What size line is coming into the house? 1/2 or 3/4"? 
If 3/4", consider changing the whole supply line to the tank to 3/4".


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## ben's plumbing (Oct 6, 2011)

yes how is right ....if inlet pipe is 3/4 don't consider changing it....DO IT....


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## Joe Tilghman (Jan 19, 2012)

I think I found the problem,There is a 3/4 pipe transiioning to 3/pex. Then there is a T 3/4 PEX goes into the floor I am assuming to supply the house then the other end of the T is 1/2 which goes to the washer.

Looking closer I then found a 1/2" PEX line coming up through the floor connecting to copper then into the cold side of the hot water heater.

This is the cause of my low water pressure correct? And now I have to find what is coming into the house.


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