Lennox air conditioner displays E227 or similar low-pressure/low-suction error; outdoor unit may short-cycle or run with poor cooling performance.

Safety: Do not attempt to add refrigerant or open the sealed system yourself. This requires specialized tools and certification.

• 1. Check air filter and airflow: Replace a dirty Lennox-approved filter. Ensure all supply and return vents are open and not blocked by furniture or rugs.
• 2. Inspect indoor coil for icing: With power off, remove the access panel to the evaporator coil. Look for ice buildup on the coil or suction line. If iced, leave the system off and fan ON for several hours to thaw.
• 3. Clean evaporator coil (if accessible): After thawing, gently vacuum loose dust from the coil fins. Use a non-acidic coil cleaner approved for indoor coils if heavily soiled. Protect surrounding components from overspray.
• 4. Restart and observe: Restore power and run cooling. If the error recurs or cooling is still weak, a leak or TXV issue is likely. A technician must locate leaks, repair, evacuate, and recharge the system to Lennox specifications.

Note: Operating with low refrigerant can overheat and damage the compressor. Shut the system down and schedule service if low-pressure faults persist.