The answer is YES you do. Even new systems need routine maintenance to keep the operating at peak efficiency.
Some items that should be checked routinely:
1. The refrigerant coils need to be cleaned thoroughly at least every six months to keep their heat transfer at an optimum performance.
2. The refrigerant level needs to be exact and checked twice a year. An under-charge or over-charge can cause harm to the system and raise utility bills and lower comfort.
3. Electrical connections need to be inspected for tightness and wear to prevent over-heating which will lead to equipment failure.
4. Duct work needs to be tested and inspected for leaks and performance. Poor duct work can cause equipment failure, poor customer comfort, and high utility bills.
5. Thermostats need to be inspected for correct installation. If the hole in the wall behind the thermostat is not sealed; the thermostat will read the wrong temperature and cause comfort issues.
6. The condensate drain pans and drain lines need to be inspected and clear for proper drainage or severer water damage can occur.
7. All components such as safety devices, heat exchangers, fan motors, wheels, and blades, compressor and reversing valves and relays need to be inspected for proper operation.
8. Keep your return air filters changed or clean every 30 days of operation. Sometimes more often depending where and how you live.
As you can see; there are many items that need to be professionally inspected and cleaned by professionals to keep your heating and air conditioning systems in top shape. Failure to routinely tune-up your equipment can lead to very expensive repair bills, high utility bills, and poor health and comfort.
A quality tune-up usually takes at least and hour or more to perform and will pay for itself.