They say you should have your central heating and A/C method tuned up and diagnosed up every single season, however well, I do not think in that! Especially when you have a brand new and undoubtedly current central heating and cooling unit like I do! Getting the Heating and Air Conditioning tune up once a year is good enough for myself and others because of this fact. It is not like the central heat and cooling system unit was defective or anything like that. If it had been I would have returned it and not just kept having Heating and Air Conditioning tune ups and check ups! My sister on the other hand needs to have her central heating and A/C method tuned up and diagnosed up every season because it is almost 10 years old. At that point in the lifespan of a central heating and A/C method you do need your Heating and Air Conditioning tune up and check up seasonal. It is the only way to guarantee that your Heating and Air Conditioning method will be toiling good through the extreme weather that will be ahead. I used to get my central heat and cooling system unit tuned up and diagnosed up every season before I got this brand new and current central heating and cooling unit. But because it is brand new and current I do not need to do it anymore, once a year will continue to be good for myself and others until my central heating and cooling unit gets to around 4 years old. Then I will go back to Heating and Air Conditioning tune ups and check ups seasonal.