Wireless sensor networks (WSN) are prone to be affected by faults which may be caused due to a variety of reasons, namely hardware malfunction, software problems, inadequate energy resources, and range or environmental hazards. A WSN is required to be equipped to handle such situations else would suffer an overall curtailment of the lifetime and ultimately not meet the required goal. Tolerance to faults thus forms one of the guiding parameters in WSN design. In this paper, we have proposed a method to find a reliable routing protocol using fuzzy logic based on Link Quality Indicator (LQI), Received Signal Strength Indicator (RSSI), and number of hops to the base station. Additional to the primary reliable path, each node has a secondary path which will be alternate path for each sensor in case of failure of the primary path. Implementation of this approach has been done as TinyOS module and evaluated through TOSSIM simulations. The experimental results show promising results in terms of packet delivery and reliability of the network.