SAN DIEGO, CALIFORNIA-Maybe you notice the house is too warm or you hear the unit running but the air doesn’t feel cold. Sound familiar? Chances are your air conditioning unit has frozen up. “Once the frost has built up in the system, it is practically useless for cooling until you can identify and fix the problem to prevent it from happening again,” says Gabriel Carini, who is an El Cajon air conditioning business owner. The culprit is usually one of the three most common causes, and Carini is going to explain how to find them and how to fix them: 1. Dirt is often the reason for a frozen air conditioning system. It might be a dirty air filter or a dirty cooling coil or an evaporator coil. A dirty air filter simply needs to be cleaned or replaced according to the manufacturer’s instructions. “Once you notice the unit has frozen up, turn it off, replace the filter and run just the fan to give the components time to thaw,” says Carini. “If the system continues to freeze up, you could be dealing with an internal problem causing decreased airflow, which means it’s time to call a professional.” 2. The unit may be low on refrigerant. Even though air conditioning systems are closed loops and the refrigerant is meant to stay inside, regular wear and tear on the unit can cause leaks. Friction against the piping, an open valve, weak joints, or loose fittings could be the source of the refrigerant leak. Obvious problems like an open valve can be easily fixed by the homeowner, but homeowners may need to call in a professional to find and fix the hidden ones. “An air conditioning services technician can come to the house, diagnose the problems, fix the leak and replenish the refrigerant, so the unit will be back to cooling your home properly,” says Carini, an Alpine HVAC service provider. 3. Something else is broken and the unit isn’t cooling right. Sometimes the reason for a frozen air conditioning unit has nothing to do with refrigerant or dirty filters. Sometimes another part of the system is defective, faulty, or broken like a blower motor or the attached relay. The bottom line here is that you need an AC repair. “If you make maintenance like changing filters a priority and have the unit tuned up once or twice a year, you can avoid the majority of problems, keep the system running at top efficiency and extend the life of the equipment,” says Carini. Call Carini Heating, Air and Plumbing’s office to schedule a tune-up appointment or service call for a repair.