Display shows F0; unit may not cool or may shut down shortly after starting.

Safety first: Unplug the unit. The sealed refrigerant system should only be serviced by an EPA-certified technician.

Steps to address F0:

• 1. Basic checks: Ensure air filters are clean and coils are not blocked. Poor airflow can mimic low-charge symptoms.
• 2. Observe operation: When briefly powered, check if the compressor starts and if the larger refrigerant line becomes cool and the smaller line becomes warm. If not, there may be a refrigerant issue.
• 3. Inspect for oil stains: Look around refrigerant joints and coils for oily residue, which can indicate a refrigerant leak.
• 4. Sensor inspection: Locate any line-mounted temperature or pressure sensors and ensure they are properly attached and wired. Replace if physically damaged.
• 5. Call a professional: If F0 persists and basic airflow and sensor checks are normal, a licensed HVAC technician must check pressures, locate leaks, and recharge or repair the sealed system. Do not attempt to open the sealed system yourself.