I was called to a home to perform a preventive maintenance check on a Burnham Alpine natural gas boiler with an indirect water heater. The boiler was over 10 years old and had not been serviced in a while. I started by checking the electrical connections and wiring to ensure they were secure. I then checked the pressure relief valve and the temperature and pressure relief settings. I also checked the combustion chamber and the heat exchanger for any signs of corrosion or damage. Finally, I checked the burner assembly and the ignition system to ensure they were working properly. I also replaced cleaned the burner assembly. The homeowner was very pleased with the work I performed and thanked me for my professionalism.