It is a good habit to do a visual inspection of your HVAC system every one or two months. You should look at the thermostat, indoor and outdoor units, registers and returns. A few hints on what to look for:

• Check the battery in your thermostat
• Is the condensate system draining properly?
• Is your flue securely attached?
• Registers and returns should be free from blockages
• Look for evidence of mold
• Is your outside unit level?