Be thorough and inspect your basement regularly by checking the following where applicable:
HVAC Systems - Check the drain pans and remove debris to allow free flow. Inspect the filters and replace whenever needed. When inspecting the HVAC, look at the duct work and seal deteriorating insulation.
Pipes Condensations - Pipes condensation is a common plumbing problem caused by sweating pipes. This problem promotes mold corrosion and rot if ignored. Insulating your pipes will reduce condensation.
Sump Pumps - Sump pump systems assist in keeping unwanted water out of your home. When checking the pump, make sure the outlet pipe is not frozen or clogged and that it directs water away from your home. Clean the air hole in the discharge line and make sure that the motor is running well. Test the pump by filling the sump pit with water to make sure the pump is working properly. Check that the pump is actually pumping out water.
Walls and Ceiling - Check the walls and look for moisture signs. Moist walls may indicate an internal leak. Look at the walls and search for stains. If you detect stains, follow them to locate the source of the problem and fix it. Even the smallest sign for a leak in the basement must be treated promptly.
Foundation - Foundations are not always waterproof. Gaps and cracks are created as the house shifts and settles over time. Landscape is also changing over time and may lead to excessive water in the soil around your home. Seek professional help if you need to make any landscape or foundations repairs.
Ventilation - When checking the ventilation systems, be sure to inspect all ventilation systems including water heater, exhaust fans, dryer vents etc. if you suspect any failure in these systems, repair it right away.