This study provides an extensive analysis of the limitations for the old generation of water and steam cycle chemistry used in boiler water treatment, using a case study of an operational gas plant running since 1977. Key failures observed included hydrogen damage (HD), high temperature stress rupture, and acid phosphate corrosion, all attributable to heavy deposits resulting from outdated boiler water chemical control program. These failures impact process production, boiler performance, and safety, prompting the need for improved treatment options. The paper recommends transitioning to modern chemical treatment methods, including the adoption of a new phosphate program, an upgrade to monitoring systems, the performance of chemical cleaning to remove heavy oxide deposits, and revision of alarm limits to accommodate the new generation of chemical treatments. By implementing these strategies, the integrity and operational efficiency of boiler units can be safeguarded, promoting the sustainable operation of aging gas plants and mitigating the risks associated with old-generation chemical programs.