We had our house repiped with Pex (in the attic) and now the cold water takes 3 to 4 minutes to get cold. We are on well water/pressure tank and live in the hot south central USA. The attic does get very hot. The Pex has a foam insulated cover around it. What can we do now? More insulation or better ventalation in the attic? Or did the plumber forget something?
Thanks

Did it do the same thing before repiping? Are you on a slab? Why did they put it in the attic because in the winter, even where you live, it will freeze. Pex can take some freezing but the water won't get through the pipe. The attic is probably 130 degrees and to get cold needs a change of 70 degrees. Perhaps more insulation would help.

It is a common problem...
You have to use proper thickness and density pipe insulation. Use the same insulation that AC contractors use to insulate their return line from condenser. Buy the thickest one available...

Also, you can use figerglass insulation used in commercial plumbing when pipes run exposed across a roof. This insulation is about 2" thick

Also, ventilate your attic. Add more fixed vents or use power vent that activates at certain temperature.

Educate yourself on types of insulations here: http://www.sandsinsulation.com/. Don't miss the instructional installation videos, too...

Back to you... Milo