Rheem Rheem Classic Series RA16 3-Ton 16 SEER Central Air Conditioner NOT STARTING Error Fix: Outdoor Unit Won't Start

Error code NOT STARTING on the Rheem Rheem Classic Series RA16 3-Ton 16 SEER Central Air Conditioner means: Outdoor Unit Won't Start. The thermostat is calling for cooling (indoor blower runs) but the outdoor condenser unit does not turn on at all. Check the outdoor disconnect — typically a pull-out box mounted on the wall near the unit. Ensure the disconnect is fully engaged. Check the circuit breaker for the outdoor unit at the electrical panel. Listen at the outdoor unit: (1) Complete silence = no power reaching the unit (breaker, disconnect, or contactor coil circuit). (2) Humming sound = the contactor is energized but the compressor or fan motor cannot start — the run capacitor has very likely failed. The run capacitor is the single most common AC repair. It is a cylindrical metal or plastic capacitor that stores energy to start and run the compressor and fan motors. Test with a multimeter set to microfarads (μF). Replace if the reading is more than 10% below the rated value printed on the capacitor ($10-25 part). (3) Clicking from the contactor but no compressor = contactor pulling in but motor still not starting, capacitor failure or compressor mechanical failure.

The most successful fix is "Test and Replace Run Capacitor" (medium difficulty, ~45 minutes). Estimated DIY cost: $15-$25. HomeMD has 2 community-ranked fixes for this error.

This error is rated warning severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Yes — the top-ranked community fix ("Test and Replace Run Capacitor") is rated medium difficulty and takes about 45 minutes. Tools needed: Phillips screwdriver, Multimeter (μF setting), Insulated screwdriver, Non-contact voltage tester.

DIY cost: $15-$25. Professional repair typically costs $150-$250. Many homeowners save money by trying the top-ranked community fix first.

The Rheem Rheem Classic Series RA16 3-Ton 16 SEER Central Air Conditioner has 7 other known error codes, including: CAPACITOR FAIL (Run/Start Capacitor Failure), CONTACTOR FAIL (Contactor Failure or Pitting), FAN MOTOR FAIL (Condenser Fan Motor Failure), FREEZING UP (Evaporator Coil Freezing — Ice on Refrigerant Lines), NOT COOLING (AC Not Cooling — Outdoor Unit Running), and 2 more.