The first step you should take when troubleshooting your air conditioning unit is ensuring that your thermostat setting is on cool rather than heat. Yes, this may sound like a no-brainer, but people forget to change this setting after the winter months more often than you would think.
There are a number of reasons why your air conditioner might be running but not cooling. It could be an issue with the thermostat, the compressor, or the evaporator coils. Or, it could simply be clogged with dust and debris, which is preventing it from working properly.
Frozen Coil
This is one of the most common air conditioner problems. There are many reasons that could cause a frozen coil. The reasons could range from low refrigerant levels to mechanical failures. We'll start with the low refrigerant issue.
#1 Most Common Air Conditioning Repair – Bad Capacitor
The fan of course makes a whirring noise, the compressor is like a deep buzz like a refrigerator running. Holding your hand above the fan should feel warmer than the outside air.
For AC capacitor replacement, anticipate spending between $150 and $400, depending on the capacitor's type and accessibility. A bad AC capacitor is a fairly minor repair, and most HVAC technicians will recommend a repair rather than replacing the unit when the capacitor is the problem.
Check these issues when the unit won't kick on: Check the thermostat and adjust the settings if it isn't set to Cool and an appropriate temperature setting to call for cooling. Examine the house circuit breakers for the AC unit and reset any tripped breakers. Check the air filter and replace the filter if it's dirty.
When you notice that your air conditioner isn't cooling, your first action should be to turn it off. This might seem counterintuitive—after all, you want your home to be cool. However, continuing to run an AC that isn't effectively cooling can cause further damage to the system.
As mentioned earlier, Freon costs about $125 – $150 per pound. Most homeowners will pay in the range of $200 to $400 for a refill, depending on the type and size of their HVAC unit.
Several factors influence how much you'll pay for labor for your next HVAC repair or replacement service. However, the average cost of HVAC labor is $75 to $150 per hour.
If you are having issues with your AC not working, checking your thermostat is the first place to start. Begin by ensuring that your thermostat is set to either the “cool”, “automatic”, or “air conditioning mode” setting (instead of “heat”). Set the temperature to a low degree to initiate the air conditioner.
An AC leak will lead to warmer air from your vents over time. In most cases this can be fixed with a proven stop leak additive to seal up any leaks. When it's time for an AC recharge, turn to AutoZone.
First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.
While there are a number of commercially available coil cleaning solutions on the market, air conditioner coils can be cleaned with a solution of a mild household detergent and water. The detergent and water mix is applied to the coil using a low-pressure sprayer.
In some cases, clogged air filters or dirty evaporator coils can also restrict airflow, forcing the AC to compensate by running at high power. To resolve this issue, it's recommended to check for clogged filters, clean coils, and consider having a professional inspect and repair the motor or fan control components.
In AC systems, the air conditioner reset button is on the outside unit's lower edge, typically close to the ground. Some models have the reset button located behind the service panel, which may require tools to remove. Reset buttons are usually red or yellow with a clear “reset” label.
Check the Power
The technician will go through a process of elimination by first checking that the breaker hasn't tripped and the unit is getting power. If you have a window AC, the technician will check that the cord is not defective and there are no frayed wires.
AC capacitors are designed to last for many years, but eventually, they will need to be replaced. On average, an AC capacitor might last between 5-20 years.
The average cost of a new condenser fan motor ranges between $300 and $700, depending on the model, your AC unit, and labor costs. While this isn't cheap, replacing your fan motors before they break can save you thousands of dollars in HVAC repair services.