Today I had the pleasure of conducting maintenance in an 8 year old Carrier system. Upon arrival, homeowner stated that the system had been working fine. I started my check by verifying system cleanliness. I found the blower assembly and ducts were dirty and needed to cleaned. I then verified all amps temps and pressures. I found the gas valve misadjusted and made the necessary adjustments. Homeowner will be going on a trip soon and plans on having the cleaning schedule when he returns.