N8N wrote:
On Dec 28, 12:29 pm, "
wrote:

Many of these pumps just return the hot water via the cold
water line. That saves a pipe run, especially convenient
for old work where you don't have access. Downside to that
is that it puts that tepid hot water into the cold line where
the sink or any other location on that run will pull it. Not
so good if you want a drink of water and get a glass of
stanky, tepid water from the water heater. So, I like the
idea of the seperate return line. You could also consider
putting it on a timer so that it doesn't recirculate all night
when rarely used. Also, insulate all pipes as you will
have a heating loop, losing energy.

I never considered that an option, because isn't heated water
technically not considered potable? I often draw a glass of water
from, say, the bathroom sink if I already have a glass and don't feel
like walking all the way back to the kitchen.


Correct on the potability. There are bacteria that grow in the water heater
that you can't BUY on the open market. Some of them ( Legionella
pneumophila, the "Legionnaires Disease" culprit), can kill you.

Never consume water from the water heater. Don't use it to wash off food.