The furnace produces a high-pitched whistling or howling noise during operation.

Safety: Turn off the power before removing panels or filters.

• 1. Filter type: If you recently installed a high-MERV filter, try a less restrictive filter recommended by Frigidaire for your furnace.
• 2. Open registers: Fully open all supply and return registers to reduce static pressure.
• 3. Check filter rack: Ensure the filter fits snugly and there are no gaps where air can whistle through. Seal any gaps with appropriate tape or gasketing.
• 4. Professional duct evaluation: If the noise persists, have a technician measure the static pressure and evaluate the duct sizing.