Water from cold water faucet goes from cool to hot to cool

tima2381

With summer almost here, I've noticed that water from my cold water faucets starts out cool, then after a few seconds, it becomes rather hot and stays that way for maybe 20 sec before becoming cool again. I guess this is due to the main water line for the house being routed through the uninsulated attic above the garage. Is insulating this line likely to help? If so, what are my insulation options?

Mike Swearingen

You can get foam snap-on pipe insulation or lay batts of regular insulation (kind with no vapor barrier on it) over the pipe or both. I would do the latter.
Good luck!
Mike

tima2381

Just to be clear, by "latter" do you mean "both" or just batts?

Also, I don't know why you would or wouldn't use vapor barrier insulation for this. Could you expand on that?

tzzzz216

Mike , Are you related to one of my customers, Tony Swearingen ,here in Marianna Fl. just wondering I see you in here alot .

Ishmael

Tima2381, you probably need to install a "heat trap" in the cold water piping that supplies the water heater. Drop the cold water feed down 12", then back up again just before it enters the water heater - put a drain at the bottom of the loop/trap. The other way is to just install a swing check in the line.

tima2381

You are talking way over my head. From what I can tell, it definitely seems related to the outdoor temperature. It didn't happen during the winter, and it improves at night. The main water line into the house is 30' of bare PEX running across uninsulated (garage) attic space, which would seem to explain it, given how hot the attic becomes during the day.

Ishmael

Yeah...if it wasn't a problem in the winter, you're probably correct.