No-heat call on 2016 Goodman single-stage furnace. Inducer was cycling on and off. Drain system was partially clogged. Performed diagnosis, took manometer readings (all in proper range), cleaned the drain and flame sensor, and tested operation. Furnace started and ran normally afterward. Since pressures were in range, this indicates the pressure switches are likely beginning to fail intermittently. System operating within spec at this time. Recommend annual maintenance.