Selective catalytic reduction (SCR) technology is being increasingly applied for controlling emissions of nitrogen oxides (NOx) from coal-fired boilers. For many power plants, temperature control becomes an essential challenge to ensure optimal SCR performance and to keep the material integrity of the SCR structure. Progress Energy MAYO Plant has a tandem boiler design with a Gross Power Generation Capacity of 2 × 400 MW. The plant decided to change their coal source to a lower HHV type PRB coal and integrated Clyde Bergemann’s SmartClean technology to deal with the changes in the coal quality and ensure a stable flue gas temperature going into the SCR. The new SmartClean technology optimized the cleaning to control the Economizer Exit Gas Temperature (EEGT) at a desired set temperature. The results of the performance tests showed that the EEGT control was successful and the temperature profile stabilized after implementing the new SmartClean technology. The new technology derives decisions and changes the cleaning strategy based on the effect of the sootblowers on the heat transfer performance rather than the traditional approach of targeting a static cleanliness level in the boiler. The performance data of the closed loop tests are presented as well as the economical justification of the project.