Burning or electrical smell from the unit during operation.

Safety first: If you smell burning plastic or see smoke, turn the unit off immediately, unplug it, and do not use it until inspected. Fire hazard.

Steps:

• 1. Initial check: For a new or long-unused unit, a slight burning dust smell for the first 10–20 minutes can be normal. If it persists or is strong, proceed with inspection.
• 2. Inspect wiring: Remove the front panel and control box cover. Look for discolored, melted, or charred wires and connectors. Repair or replace any damaged wiring harnesses.
• 3. Check motors and capacitor: Smell near the fan motor and capacitor. If either is very hot or shows signs of melting, replace the affected part.
• 4. Tighten connections: Ensure all screw terminals and spade connectors are tight to prevent arcing.
• 5. Professional evaluation: If you cannot locate the source or if the main PCB appears burned, discontinue use and have the unit inspected by a qualified technician.