Is it normal for hot water pressure to be lower?

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wrybread

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At my kitchen sink I have significantly lower water pressure from my hot water than my cold water. Probably at my shower too.

Is that normal?

My cold water fills a gallon jug in 39 seconds, the hot water fills it in 55 seconds.

I'm ultimately trying to increase the low water pressure in my shower, and I think the hot water line is the culprit.
 

breplum

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Likely the pressure is identical.
Likely the flow is lower. Often, accumulated scale in hot water pipe is one reason, another can be devices on the water heater that attempt to prevent heat loss. Sometimes a floating ball, sometimes rubber flaps.
Or just clogged angle stop. Lots of homes have copper piping but stupidly, galvanized nipple at the wall stub out on the angle stop.
 

wrybread

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Interesting point about build up.

I've been meaning to re-do the hot water line for awhile now, it's old PVC with a lot of adaptors and lots of places for the flow to be restricted. And it's old and brittle and an accident waiting to happen. I was thinking about redoing the hot water section with 1/2" PEX. It's a pretty simple job, it's just a water heater with a nearby bathroom sink and shower and a nearby kitchen sink, not a whole house.

Do folks here think PEX is a good idea for this?

And if so would you use 1/2" or 3/4"?
 
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hukre

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I would recommend 3/4" PEX. The inside area of 3/4" PEX is about 25% larger that that of 1/2" PEX, which is even smaller than that of 1/2" copper.
 

wrybread

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My current plan is 3/4" pex going to the shower, since that's where I want the maximum water flow, and 1/2" for everything else. Do folks agree?

And I wonder if I need 3/4" on the cold line as well? Or is it enough to just have the shower's hot be 3/4"?
 

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