When you are having an air conditioner it is obvious that there will be times when your AC does not function well. This is when you might have to call in an HVAC expert. However, calling in an HVAC expert involves quite a lot of expenditure. Hence, it is better if you have a fair idea of some the DIY repairs to tackle the situation when your air conditioner does not blow out cool air or stops functioning completely. This way you will be able to save quite a lot of money.Let us have a look at the things that you can do to prevent unnecessary expenditure on your HVAC unit.First of all, you can check the breaker. It might have tripped off when too many appliances run on a single breaker. If you find it tripped, just replace it and your AC will start functioning once again. This way you can get back your cool air without calling in an HVAC contractor.You can also check the settings of the AC. All air conditioners have a temperature control and “fan only” option. You need to make sure that the AC is set at the “cooling” mode and not at the “fan only” option. At the same time, the thermostat should be set at a temperature that is lower than the ambient temperature of the room.Air filters are integral features of air conditioners and it is best to clean it at regular intervals because dirty and clogged air filters can cause severe problems to the air conditioning unit. Along with air filters, the duct work also needs to be checked for any kind of clogging.Last but not the least; the entire HVAC unit should be thoroughly cleaned at times before calling in an HVAC professional.