Outdoor unit runs briefly then shuts down, status LED on control board flashes E1, cooling is intermittent

Safety first: Shut off power at the outdoor disconnect before cleaning or working near the fan. Do not attempt to connect gauges or adjust refrigerant charge unless you are EPA-certified.

Steps:

• 1. Inspect airflow around unit: Ensure at least 2–3 feet of clearance on all sides and 5 feet above the condenser. Remove leaves, grass clippings, and debris from the coil guard.
• 2. Clean condenser coil: Remove the top grille/fan assembly carefully without straining the fan wires. Use a garden hose with moderate pressure to rinse the coil from the inside out. Avoid bending fins. Let dry and reassemble.
• 3. Check condenser fan operation: Restore power and call for cooling. Confirm the outdoor fan starts immediately and runs at full speed. If the compressor runs but the fan does not, the fan motor or its capacitor is likely failed.
• 4. Inspect high-pressure switch wiring: Locate the high-pressure switch on the liquid line near the compressor. Verify its wires are firmly connected and not damaged.
• 5. Reset fault: Many Armstrong Air boards will auto-reset after the pressure switch closes and a power cycle. Turn power off for 5 minutes, then back on and test.
• 6. If E1 returns quickly: The system may be overcharged, have a blocked metering device, or a serious airflow issue. These require professional gauges and superheat/subcooling checks—contact an HVAC technician.