Each controller has a default 4hr timer off countdown. When the controller is operating on Bluetooth and connection has been idle for 4hrs, the heaters for this specific controller will switch off. This interval setting can be changed to 2, 4, 6, 8 or 12 hours or disabled. Each controller has its own individual settings. To change this, go to the site configuration menu, edit site, select the controller, click the controller name to go to the detailed page. At the bottom there will be a dropdown list to change the value. It is recommended to not disable this setting.