**Furnace Maintenance** **Work Performed:** - Performed annual maintenance on 14-year-old Gibson single-stage furnace. - Completed full inspection and combustion analysis. - Verified all safety controls and operation. **Results:** - Combustion test showed approximately 90 ppm CO in the flue gas - Slightly elevated CO indicates possible partial clogging in the secondary heat exchanger. - Igniter showing higher-than-normal amp draw but still operating correctly at this time. **Recommendations:** - Continue with annual maintenance to monitor CO levels and secondary heat exchanger condition. - Be aware that the igniter may fail in the near future and could require replacement.