We set our thermostat on manual as low as it will go (54*), turn the water heater off, and shut the water off to the house. We have an automatic dialer that will call out if the temperature drops below 45* or if the electrical power is interrupted. We have it set to call my cell phone first, but it will automatically roll over to a friend's phone if I don't answer. He's the one who looks in on our house a few times a week while we're gone. It's worked well, so far.