[C320-list] Hot Water Heater

[Timothy Osburn]

Ok, I realize this question will put in contention for the "Mr. Potato Head
Award", but engaging in nitwittery is one of my few fortes, so here goes:

When the shore power is plugged in, the hot water heater is on. The
electric panel has a breaker ( but it's not a rocker switch ) that is
marked "Water Heater" so using both my brain cells, I've deduced that this
is actually related to the water heater in some way. However, when I push
it in, nothing seems to happen. Pulling on it doesn't do anything either (
I thought pulling it out would turn the breaker off ). So, how does
everyone else turn their water heater off?  Or do you just leave it on all
the time?  What am I doing wrong ( ...specifically as it relates to the
water heater otherwise we'll be here all day... )?

Thanks!