I've had that call a lot of times, especially on large systems where the programs just back up so there is always something turned on. It's usually the gardeners that set it wrong. One of the things I love about Weathermatic Smartline is the hidden start times so they can't add multiple start times unless they go to "Advanced Menu". But then you get the phone call saying "I can't set anything except zone 1. Can you come NOW and fix it?"