I've got a small cottage that's usually used only one or two days a week. We control the heat pump remotely via the Pebble Air controller and app. When we're away the heat pump is off. Returning on a winter's day after several days' absence, we can start the heat pump a couple of hours before we arrive and enter a warm cottage.
The hot water cylinder is electric, and it seems a waste of energy and money to keep it operating when we are routinely away for several days at a time. But the HWC is hard-wired to a 30A (if I remember correctly) breaker, and I haven't seen any device (30 A rated WeMo or the like) that would allow us to control it as we do the heat pump.
What devices exist to allow remote control of a HWC? (disregarding the power utility's ripple controller)