I never used these heat trap nipple before. I am installing them on a electric water heater. Do the flaps need to be installed up or down?

Hi PG22

If the direction of flow isn't marked on the nipple itself (check for an indentation/mark) then it doesn't matter what direction you install them in... ;)

Mark

These are what you're talking about right? NTom

Hi PG22

If the direction of flow isn't marked on the nipple itself (check for an indentation/mark) then it doesn't matter what direction you install them in...;)

Mark thank you very much :-)

Those aren't the heat trap nipples PG22 was talking about, Tom. He was literally talking about heat trap nipples with neoprene flappers inside of them... make less noise then the older ball style nipples you posted, and they can't get stuck up like the older ball style, too!

Mark

Thanks for the lesson Mark. I can always count on you to keep the old man up to date. Cheers, Tom