I do 30 days on residential. All most all call backs happen a day or two after the service. The only time I ever have a call back is when something is broke and someone didnt what to pay for the See Snake.When I do go back "not very offen" use the see snake first. If it is broke they pay for the video work. I have a stamp in the truck that says NO 30 DAY in big red letters. I dont use it much but its a nice out.