Initial inspection if furnace shows that code 3 is active. Code 3 is for pressure switch or inducer error. Further inspection of unit showed that the intake mesh is partially clogged with leaf and bug debris. Inspection of outdoor termination shows that the intake flange is partially clogged with snow and ice. Remove debris from mesh and snow from outdoor intake and test run operation of unit. System is draining water correctly and inducer motor is operating properly. No other issues found or suspected while on site.