Pulverised coal combustion continues to be one of the main conventional methods of producing electricity over the last several decades. Mineral matter present in coal is usually present as free ions, salts, organically bound inorganic and hard minerals. During coal combustion these minerals partly vaporized, coalesce or fragment. The mineral matter in coal transforms into ash during combustion leads to ash deposition causing problems such as fouling and slagging. This deposited lumps called clinkers, mainly in radiation zone directly exposed to flame radiation resulting to slagging, while sintered deposit in convection zone not directly exposed by flame radiation called fouling. The paper deals with slagging measures and clinker formation in a typical 300 MW boiler using commercial code FLUENT and several available empirical indices. The propensity of the slagging with the used coal is calculated by different thermal indices. Temperature distribution, velocity profile and particle trajectories were analysed to find out the most probable zones likely to experience clinker formation. The most probable spots for slagging were found in radiation zone near to nose of the furnace and left-top side superheater tubes which agrees with the plant observations. However, the propensity of deposited ash obtained from the plant is seemed low-medium using several indices. The results from this investigation demonstrate the usefulness of modeling approach in identifying the probable zones of clinker formation which proves to be valuable for power utilities to adopt corrective measure for soot blowing to clean the ash deposits before it grows bigger in size.