So I got clarification on the water heater situation. In the past
they had an instant on water heater and it was disliked. After a
kitchen remodel they looked once again at one of these but realized
that their new sink does not have a hole for another dispenser of any
type. So in order to get hot water fast they need a small water heater
that is inline with the regular hot water line and comes out of the
faucet. That's why the one in my shop intertested them so much,
because that's how I have it plumbed. This means that even if the hot
water isn't being used in the sink the water in the small tank may
cool enough to turn on the heating element while the diswasher is
running. That's why the need for something to prevent the heater from
coming on when the dishwasher is running.
Thanks to everybody who tried to convince me the desired relay
device wasn't needed but it still turns out that it is needed. So,
anybody know of one?
Eric