Plan to do cooling and heating system maintenance four times a year -- twice each winter and twice each summer. Keep this checklist handy for your routine maintenance:
* Inspect belts and blowers. Change worn-out belts. Oil blower bearings.
* Clean or replace filters. Some filters need to be cleaned monthly. Check your owner's manual for guidance.
* Clean and clear drains, traps and drip pans.
* Clean outdoor and indoor coils.