Check and replace humidifier filters
Remove grills on forced air system ducts and vacuum inside the ducts
Examine the foundation for any cracks
Examine exposed wood (for instance, in the attic) for insect damage and do any insect preventive maintenance that needs to happen
Test all ground fault circuit interrupters
Check all vents (inside and outside) and make sure there are no obstructions
Remove screens, clean window wells, and dry them
Examine all outdoor items and see whether any seasonal maintenance needs to be done
Drain off a pan full of water from the clean-out valve at the bottom of your water tank (removes sediment and maintains efficiency)
Check your sump pump for any issues
Test all fire / smoke / carbon monoxide detectors in the house
Check all window and door locks to ensure they’re all in working order
Check your fire escape plan and make sure that furniture additions haven’t changed this
Check all faucets for dripping water and change washers if needed