Restore care safely
Only handle the parts the user manual identifies for homeowner care, and only if you can reach them safely. Do not reach into the fan, touch the coil fins, wash the inside of the head, or improvise with a harsh cleaner. If you are uncertain how to isolate the unit or remove its filter, have a qualified technician demonstrate it.
Ask for a written care schedule suited to your equipment and home. Include which filters you have, the cleaning or replacement method, and how to tell that each needs attention. A photo of a clean filter can give you a useful reference. Keep the air inlet and outlet free of household objects.
Separate dust from energy use
Save the electric bills showing usage in kilowatt-hours, not just the amount due. Add the indoor setpoints, which heads ran, outside temperatures during the concern, and any backup heat use. Note whether the room was actually comfortable or whether the unit struggled to reach the setting. A colder winter or rate change should not be confused with a proven equipment failure.
For dust, tell the technician where it collects and whether renovation, pets, or another indoor source changed. Do not treat dirty filters as proof of the source of every particle in the room.
If heating remains weak or use still concerns you after proper care, request a performance visit. We would want a check of the equipment's condition and operating measurements, with a written explanation of any recommended work. More aggressive cleaning, a refrigerant adjustment, or replacement needs its own evidence.
Your next step: Complete the exact manual's normal filter care safely, record the usage and comfort concern, and arrange a qualified performance check if it continues.