Your HVAC system is one of those unsung heroes at home. When it works well, you hardly notice it. When it starts to weaken, it becomes a big problem. Your HVAC system is responsible for keeping your home comfortable no matter the temperature. If you find that your house is too cold in the winter and too hot in the summer, it is probably time to do some HVAC maintenance. It is important to know whether to repair or replace your HVAC system in the event of a malfunction. This may involve a professional assessment and some checks that you can perform as well. Always check with a trusted professional before deciding to repair or replace your HVAC unit to save time and money. But here are some general tips on whether you can give your HVAC unit a tune-up or if it's time to buy a new unit.