Upon inspection, it was determined that the boiler's aquastat and gas valve required replacement. I promptly returned to address these issues. The aquastat, responsible for regulating the water temperature, was replaced to ensure efficient boiler operation. Additionally, the gas valve, which controls the flow of gas to the burner, was replaced to maintain safe and reliable performance. Furthermore, the thermal fuse had blown, indicating an unsafe flame rollout system. This critical component was replaced to prevent any potential hazards and ensure the boiler operates safely.