A furnace filter is a small part of the system and the easiest one to forget. Nobody notices it until the rooms feel stuffy, the unit runs longer than it should, or the air carries more dust than before. St. Louis summers and winters both put the unit under load, so the check matters in both seasons.
Local option: New Plan Care gives families in the St. Louis area in-home help so a parent can stay home: companionship, help with bathing and dressing, meals, and overnight care. Call (314) 405-0887.
Who buys the filter?
The household does. Put the filter size on the house sheet, keep one spare on a shelf the next person can find, and buy them in pairs so the spare never runs out at the wrong time.
How do you know the size?
Read the size printed on the cardboard frame, usually along one edge. Write it on the house sheet and on a label inside the furnace closet. If the frame is gone, measure the slot before you buy.
How often does it change?
Follow the interval in the unit's manual or the filter's own label. Write the date of each swap in marker on the frame, so the next check uses a real date and not a memory. A home with pets or heavy dust may need a shorter interval, so ask the technician who services the unit.
Who swaps it?
Decide that in writing. A family member can swap it. A caregiver may swap it only if the agency's paper allows household tasks like this and the family has shown the steps. Some agencies will not touch the furnace at all. Ask before you assume.
How is the swap done?
Turn the unit off at its switch before you open the cabinet. Note the arrow on the old frame, which shows the way the air moves. Slide the new filter in with the arrow pointing the same direction. Write the date on the frame, turn the unit back on, and listen for a normal run.
Who calls the repair company?
Name the person and the phone number on the house sheet. Ask the technician to check the filter at every visit and to write its condition on the service slip. If nobody owns the call, the first sign of trouble arrives as a bill nobody expected.
What if the person who tracks it leaves?
Hand the job over in writing: the house sheet entry, the spare filter location, the size, and the reminder on the calendar. The task that fails is the one that lived only in one person's head.