Posted on: September 30, 2015An air conditioner that isn’t working properly is a major problem, particularly in the hot summer months. It can cripple your home, and if it’s hot enough, even require you to spend the night elsewhere. It’s important to properly maintain your air conditioning system with cleaning, air filter changing, inspections, and other essential maintenance, but even the best maintained units will sometimes go awry. Read on to find out what the most common air conditioner problems are — and how you can fix them. The problem: Air isn’t coming out of the registers. How to fix it: If no air is coming out, the fan on the outside unit may not be running. Believe it or not, this is an easy problem you want to have, as it typically means that the breaker is simply tripped and needs to be reset. Or you may have another easy problem: the blower belt, which will simply need to be replaced. Other causes include a problem with your thermostat, control board, or wiring. Your condensate pump reservoir may be full as well. The problem: Your air conditioner isn’t coming on at all. How to fix it: An air conditioner that simply won’t come on may indicate a problem with the thermostat. Set your thermostat to cool and bump down the temperature setting, then check your electrical panel for a tripped breaker or blown fuse. Check for issues in power supply by looking at wires. You can also check your furnace power switch and thermostat for any problems. The problem: The air conditioner isn’t cooling. How to fix it: An air conditioner that is running but isn’t cooling is one of the most common problems. Unfortunately, it has a number of potential causes. It could be a dirty air filter, low refrigerant level, or a blocked condensate drain. You can also check for ice around the coils or a dirty outdoor compressor. Or, you may need to add more coolant to your system. Another problem: it may simply be too hot outside to cool your home to your liking. Most air conditioner can only cool to about 20 degrees lower than outside air temperatures. The problem: You’re low on refrigerant. How to fix it: Air conditioners that don’t cool properly may be low on refrigerant. This could mean that it was undercharged, or, you may have a leak. Check for any leaks before adding more refrigerant, as problems with leaks will persist, and they can be harmful to the environment. The problem: Your air conditioner is blowing hot air. How to fix it: An air conditioner that is blowing hot air can be infuriating. Often, the problem is with a dirty air filter, as this can cause flow problems. Verify that the outside unit is running, and check to see if there are leaves or other debris obstructing air flow. Another issue may be that you’re low on freon. The problem: The unit is leaking. How to fix it: Air conditioning units create condensation, which is typically drained properly. But sometimes, pipes can leak or be blocked, or the condensate pump may stop working. Try clearing your condensation drain pipe, clean the pump system of algae with a bleach solution, check the electrical connection to the condensate pump, replace the pump, and check your condensation drain pipe for leaks. The problem: The compressor won’t run. How to fix it: A compressor that won’t run could indicate a burned wire, defective start capacitor, or simply a defective compressor. You should adjust your refrigerant charge, clean the condenser coil, check the capacitor, and replace the compressor if it won’t reset. The problem: The air conditioner never turns off. How to fix it: Even when it’s extremely hot outside, your air conditioner should turn off occasionally. An air conditioner that runs continuously can indicate a problem with the fan. Turn the thermostat fan to the off position to see if you can stop it that way. It’s also a good idea to check refrigerant levels and relay switches. The problem: The air conditioner is making a strange noise. How to fix it: Air conditioners make noise, but sometimes, they’ll make a noise you don’t recognize, and that can indicate a problem. Strange noises may be a mystery, but often, a noisy air conditioner is a belt problem, particularly if it’s making a squealing sound. The belt may be improperly aligned or need replacing. A grinding noise typically indicates a problem with the motor’s bearings. Pinging or popping may be a loose flap of metal in the duct work, and rattling noises may indicate that you need to tighten cover panels. The problem: The fan isn’t working. How to fix it: If the fan in your outdoor unit isn’t turning, your air conditioner will not cool properly. Press the overload or reset button to try to reset it. Or, with the unit turned off, try to spin the fan blades clockwise. If they spin freely, you may have a problem with the capacitor and need to replace it. The problem: The condenser isn’t running. How to fix it: Be sure the condenser is getting power. Verify that the unit is plugged in and there isn’t a blown fuse or tripped circuit breaker. A condenser that won’t run may have problems receiving the cooling control signal from the thermostat. You should also check for safety switches and the oil level. Check for refrigerant pressure, because if refrigerant has leaked, the low pressure safety may have been switched. The problem: The unit turns on and off constantly. How to fix it: An air conditioner that comes on and off again a number of times repeatedly is signaling a problem. Most likely, your condenser unit is dirty or blocked, and you may also have a dirty evaporator. Check both for obstructions and give your entire air conditioning unit a cleaning to clear any debris. The problem: The coil is frozen. How to fix it: A frozen coil means your air conditioner is working overtime while your house stays hot. Check for airflow problems in dirty air filters, or obstructions in return air ductwork. You should also check your refrigerant level, as well as your blower fan, which may be malfunctioning. The problem: The unit trips the circuit breaker. How to fix it: If your air conditioner constantly trips the circuit breaker when it comes on, it will not work. You may have a weak breaker that needs replacing or need to have your compressor properly grounded. Your condenser fan motor may be shorted, or you could have a defective capacitor. The problem: Some rooms are warmer than others. How to fix it: If you have some rooms that are chilly while others remain hot, your system air is likely unbalanced. Use dampers to balance the system so that your home is uniformly cool. The problem: There’s an unusual odor coming from the unit. How to fix it: An electrical odor may come from overheating parts, such as a blower motor or seized bearings or loose electrical connections. You may also have restricted airflow causing electrical overheating, which means you need to replace your air filters. A burning odor may be caused by debris in the duct work or at the unit. The problem: The thermostat is never correct. How to fix it: You’ve set your thermostat for a certain level, but it’s never actually there. Typically, this means your thermostat isn’t properly calibrated, but even after being recalibrated, thermostats can lose their calibration again. Simply replace your older style thermostat with a digital thermostat that is accurate and doesn’t lose calibration. If you’re stuck with a broken air conditioner and stumped on how to fix it, calling a local repairman may be your best course of action. With a home warranty plan in place, it could also be the most cost effective.