To improve the thermal performance of vertical heater, orifice plugs were installed on tube side at bottom to improve the heat transfer coefficient. These orifice plugs act as an ejector at the tube side and thereby increase velocity of process fluid, thus improve the heat transfer coefficient. These orifice plugs play an important role in the thermal performance if the tubes are properly cleaned. Tube cleaning is more crucial with vertical layout of tube bundle with orifice plugs in urea plant. In this article, an attempt has been made to highlight the operating experience and problems faced with orifice plugs in vertical layout of rectifying column heater, called recirculation heater at the urea plant of IFFCO Kalol unit. Also, efforts have been made to share the in-house modification implemented to remove the operating bottlenecks with orifice plugs and the benefits achieved with improved performance of recirculation heater of urea plant.