For industrial processes, namely, power systems, chemical systems and oil refinery systems, the boilers play an important role in the overall plant operation. If they are operated continuously for an extended period of time, then due to chemical reactions, aging and stress caused by the heating process, there are problems of corrosion, slag precipitation and leaks in different components. This deterioration invariably leads to a reduction in the amount of steam generated, equipment damage and, in some cases, complete plant shutdown. This paper presents a survey on recent patents, which deals with monitoring and control of corrosion, slag as well as different leak detection schemes. The focus of this survey is on slagging and corrosion control in superheated tubes of the waste to energy (WTE) boilers as well as monitoring the corrosion of carbon steel in boiler-drum. For different leak detection schemes, it is well known that most of them generate false alarms. Therefore, some new inventions on the maximum number of false alarms tolerated by the system and the acceptable operation of the leak detection systems are also presented.