For those interested, I’ve created an event-driven app that can be used for @pizzinini 's use case, and for many others - like:
- turn on demand when bathroom door closes, off when it opens
- demand when motion detected near the kitchen sink
- demand when the laundry room light is switched on
- demand when a pocket door starts moving (I have pocket doors on 2 of my bathrooms)
- demand every XX minutes
- DON’T demand if the return temperature (as read by any ST temperature sensor) is above a set temp
All only when the location is in “Home” mode (or whatever you desire). The idea being (of course) to run the recirculator just prior to when you need hot water.
http://community.smartthings.com/t/green-smart-hot-water-recirculator/7085
And for those interested in this kind of thing, I highly recommend looking at RedyTemp recirculation systems.
Their basic unit can be installed to run until the return temperature (as measured by a stainless steel temp sensor installed in the water pipe) reaches a settable temperature. This one is partcularly money saving - you can keep your water hot, but stop pumping once the temperature is reached. I’ve mimicked this in my SmartApp, and added the ability to turn demand on when the temp falls below the target.
Enjoy!