Performed a 2 system homecare on 2 hvac systems. I inspected heat exchanger, burners, and ignition components for safe operation. I checked blower assemblies and got great temp rise readings. Flushed drain lines also. Both system heat well. The carrier system needs a new flame sensor and a piece of indoor air quality device. Without an indoor air quality device, airborne particles are circulating through the system and settling on the blower wheel. And ionization system like a iWAVE help reduce buildup by neutralizing particles,odors,bacteria and viruses before they reach the blower wheel.