Indoor unit stops and A3 error appears; sometimes accompanied by water dripping from front panel

Safety: Switch off power at the breaker. Water may spill when opening the unit; place towels or a tray underneath.

• Check drain pan: Remove the front cover and inspect the condensate tray under the evaporator. If full of water, the drain is blocked or the pump is not working.
• Clear drain line: Locate the drain outlet and hose. Use a wet/dry vacuum at the hose end outside to suck out sludge and algae. Flush with warm water and a mild disinfectant.
• Inspect pump and float: On models with an internal pump, access the pump assembly. Clean any slime or debris around the float switch. Ensure the float moves freely up and down.
• Check pump power: With power restored briefly and great caution, listen for pump operation when the tray fills. If the pump is silent and receiving voltage (technician check), replace the condensate pump.
• Re-route hose: Ensure the drain hose slopes continuously downward with no upward loops or kinks.

After cleaning and reassembly, reset power and test cooling. If A3 returns, the pump or float switch assembly likely needs replacement.