Display shows PF and the unit stops cooling after a power interruption or brownout.

Safety first: Turn the unit OFF and unplug it before inspecting the cord or outlet.

• 1. Confirm power stability: Check if other appliances on the same circuit are working normally. If lights flicker or other devices reset, there may be a supply issue—contact an electrician.
• 2. Reset the unit: Unplug the De'Longhi air conditioner for 5 minutes. Plug it directly into a wall outlet (no power strip or extension cord). Turn it back on and reselect the mode and temperature.
• 3. Inspect plug and cord: Look for burn marks, cuts, or kinks in the power cord and plug. If any damage is visible, stop using the unit and replace the power cord assembly.
• 4. Check outlet: Plug in a lamp or another small appliance to verify the outlet is live and stable. Avoid using GFCI or AFCI outlets if the manual advises against it.
• 5. Surge protection: If PF occurs repeatedly after storms or grid events, use a quality surge protector rated for the unit's amperage, or consult an electrician about line conditioning.

If PF appears constantly even with stable power and a known-good outlet, the main control board may be misreading voltage and should be inspected or replaced by a technician.