BarkBlaster requires 8 D Cell batteries (not included with initial purchase).
The unit attaches directly to your standard garden hose (not included with initial purchase).
Yes, it has default settings, so it will operate when powered up.
Remove the Batteries, wait 10 seconds, replace the batteries. This should reset the BarkBlaster
Yes, you may have to set the sensitivity level to the highest number with the App.
Try adjusting the level to 600.
If you start to use the BarkBlaster before it turns cold, remove the hose and the Beeper should make your dog quiet down. Typically this will last several months until it is warm enough to use the water again.