I was called to a home to perform a routine maintenance check on a Viessmann natural gas hot water boiler with an indirect water heater. The boiler was over 10 years old and had not been serviced in several years. During the maintenance check, I inspected the boiler for any signs of wear or damage. I also checked the pressure relief valve, temperature and pressure safety controls, and the combustion chamber for any signs of corrosion or damage. I also checked the indirect water heater for any signs of wear or damage. I tested the water heater to ensure that it was producing hot water at the correct temperature and pressure. After completing the maintenance check, I provided the homeowner with a detailed report of my findings and recommendations for any necessary repairs or maintenance. The homeowner was pleased with the service and agreed to schedule a follow-up maintenance check in the future.