Wireless sensor networks (WSN) are self-organized systems consisting of large number of heterogeneous/homogenous sensor nodes that are deployed in inaccessible/harsh environments where nodes are susceptible to damage. The sensor nodes are deployed in unwelcoming conditions to collect data through wireless medium and monitor the environment. The fault tolerance in WSN is the critical issue now-a-days but WSNs reliability is constrained due to faults in hardware and communication. Faults may be due to link failure, nodes failures, battery drainage, environmental hazards, asymmetric links, imperfection in hardware or software, misplacement of sensor nodes etc. To obtain high data reliability and accuracy researchers have proposed many fault detection and recovery mechanisms to preserve energy for network lifetime improvement and to minimize failures in WSNs. In this paper, we present a survey on fault detection and recovery mechanisms in WSNs. Exquisite survey on different types of faults and relevant fault tolerant approaches are presented to support sensor applications.