It is to prevent siphoning the water back out of the heater if the water
pressure is lost. It makes no difference which way it is turned.
Don Young
"larry moe 'n curly" wrote in message
oups.com...
The plastic dip tube in my heater was made with a 1/8" hole a few
inches from the top. What's the purpose of this hole, and what
direction should it face?