Kaal Sarp Yantra should be installed and worshipped if a Kaal Sarp Dosha is present in a person's horoscope. A person having this Dosha in his / her horoscope is unable to have a steady growth in his / her life and have to undergo several ups and downs in life. Apart from this, he / she may also not get the good results of various good yogas / good placement of planets in horoscope due to this Dosha. A person having a Kaal Sarp Dosha in his/her horoscope suffers from mental anguish, problems in acquiring wealth, problems in having children and a very disturbed married life. There are bad dreams which regularly haunt the native along with various types of unknown fears and worries. His talents are not rewarded properly, success is delayed and his progress in life is hindered. There may be sudden monetary losses or a loss of prestige, job, business etc. There may be diseases of many types and even the best medical care may not be able to provide a full or a desired results as per Ancient Vedic Texts.
A Kaal Sarp Yoga is formed in a horoscope when all the seven planets, i.e. Sun, Moon, Mars, Mercury, Jupiter, Venus and Saturn are placed in between the Rahu and Ketu. This is supposed to be a very bad Yoga and if someone is having a Kaal Sarp Yoga in his/her horoscope then a Kaal Sarp Yantra should be installed to pacify the negative effects of Kaal Sarp Dosha otherwise the native suffers throughout the life. All his progress is hindered, big opportunities lost and even the family of such a person suffers due to this Kaal Sarp Dosha in his/her horoscope.
Kaal Sarp Dosha are of 12 types depending upon the situation of Rahu and Ketu in various houses of the horoscope. A Kaal Sarp Yoga is known as a PURNA KAAL SARP YOGA when all the seven planets are between Rahu and Ketu. However if one of the planets escapes out of this Rahu Ketu axis or is present in this axis itself then it is known as a PARTIAL KAAL SARP YOGA. A Purna Kaal Sarp Yoga is more dangerous and harmful as compared to a Partial Kaal Sarp Yoga.