Most carpet manufactures recommend a professional carpet cleaning every 12-18 months with a hot water extraction process. This will vary however depending on the usage your carpet gets. Factors include number of people, pets, outdoor environment and how well carpet is maintained between cleanings. We also advise you check the warranty information on your carpet. Many carpet manufactures require you have your carpets professionally cleaned every 12-18 months in order to keep the warranty valid on your carpet.