. >> reporter: hot water extraction, dry carbonation, all techniques to use carpets. >> the best bet is to follow your carpet manufacturer's recommendation, you don't want to risk voiding your warranty. >> most can with stand cleaning methods, about fast, the longer it sets the longer to remove the stain. have them professional cleaned once a year. >> always be careful when you hear promotions for carpet cleaning. never go with an estimate that sounds too good to be true. you want to make sure you get the right estimate. >>> another tip, take your shoes off. that will help your carpets last for years, if it's loose, consider getting it stretched. loose carpets wear faster. you want to replace, but when? >> the time to replace your carpet is when you get it professionally clean and don't like the results, once it is dirty enough you can't get the results you would like to have. >> follow these tips, it would be years before you have to worry about that. >>> for tips on hiring a professional carpet cleaner, go to abc2news.com, click on the angie's list link. >>> a professor was killed