When Los Angeles summer hits, air conditioning is a necessity. However, what if your AC isn’t cooling? It’s frustrating, especially when you need relief from intense heat.
If your AC is running but not cooling, or you’re wondering why your AC isn’t blowing cold air at all or blowing hot air, there are several common causes. Understanding these issues and how to troubleshoot them can save you time, money, and the discomfort of sweltering heat.
In this guide, we’ll explore 7 common causes of AC problems. We’ll explain why they happen and provide actionable solutions to help you keep your home cool, even in the hot months. As a local Los Angeles HVAC expert, we’ll also offer insights into the region’s unique challenges and how they impact your air conditioning system.
| Season | Task | Why It Matters |
|---|---|---|
| Summer Prep (March-May) | Clean condenser coils | Removes pollen/smog buildup, improving efficiency |
| Check refrigerant levels | Low charge increases energy use by 15% | |
| Seal ductwork | Prevents 30% cooled air loss in attics | |
| Winter Prep (October-November) | Inspect heat exchangers for cracks | Prevents CO leaks |
| Clear vent pipes of bird/rodent nests | Common issue in SF Valley | |
| Test ignition systems | Critical for older Glendale furnaces | |
| Spring/Summer | Replace or clean air filters (monthly) | Essential during peak smog/pollen seasons |
| Schedule AC tune-up | Includes coil cleaning, refrigerant check, thermostat calibration | |
| Clean and inspect outdoor condenser units | Ensures optimal performance | |
| Seal and clean ductwork | Improves energy savings | |
| Fall/Winter | Furnace maintenance | Inspect heat exchanger, test safety controls, replace filters |
| Duct cleaning | Removes summer dust and allergens | |
| Thermostat check and calibration | Ensures accurate temperature readings | |
| Schedule professional HVAC tune-up | Prepares system for cold weather | |
| General Tips | Clean/replace filters monthly | Critical during summer and wildfire season |
| Schedule coil cleaning | Especially important in coastal areas | |
| Set thermostat to energy-saving temps | 78°F in summer, 68°F in winter | |
| Install smart thermostat | Enhances control and energy savings | |
| Seal leaks in ducts and doors | Prevents cooled air from escaping | |
| Winter Specific | Schedule furnace tune-up | Avoids system failures during cold snaps |
| Inspect/test carbon monoxide detectors | Ensures safety | |
| Clean/check heat exchangers and blower motors | Maintains heating efficiency | |
| Ensure proper insulation | Reduces heating needs | |
| Watch for uneven heating | May signal duct or system issues | |
| Signs of System Issues | Inconsistent heating | Rooms heating unevenly could indicate HVAC problems |
| Strange noises (banging, rattling) | Requires immediate attention | |
| Increased energy bills | May signal system inefficiency |
Let’s delve into our unique climate. Los Angeles County is not just about sunny days and beaches. We endure blistering summers, often with unpredictable temperature fluctuations, and air quality issues due to wildfires and urban pollution. These factors can significantly influence the performance and lifespan of your HVAC system.
Now, let’s get to the heart of the matter. Here are seven common reasons why your AC is running but not cooling, along with practical solutions:
One of the most common reasons for AC not cooling is dirty air filters. Air filters trap dust, dirt, and allergens, ensuring clean airflow through your HVAC system. Over time, these filters can become clogged and restrict airflow, making your AC unit less efficient. The problem is exacerbated in Los Angeles County during wildfire season, where smoke-derived PM2.5 particles clog standard air filters.
General Maintenance
If you’re unsure how to replace the filter, consult your AC manual or a professional HVAC service.
Pro Tips:
Refrigerant is crucial for heat exchange, absorbing and exchanging indoor heat outside. Low refrigerant levels—typically caused by leaks or improper installation—can lead to several issues:
Professional intervention is required. Contact a licensed HVAC contractor to:
Increased AC use during smoke events strains refrigerant systems. During preseason maintenance, request technicians to:
The evaporator coils absorb your home’s heat. If these coils freeze, they won’t absorb the heat properly, and your AC will stop cooling. Lack of airflow, dirty air filters, or low refrigerant levels typically cause frozen coils.
Turn off the air conditioner if ice forms on the coils and let it melt. Check the filters to see if they are clean or replaced as needed. If the coils continue to freeze, it’s time to call an expert to check for refrigerant leaks or other underlying issues.
In Los Angeles County, high temperatures and humid conditions can cause frozen coils. Regular maintenance and filter replacements will prevent this issue.
You may not have a problem with your air conditioner, but it’s your thermostat. The thermostat malfunctions can prevent your AC from cooling effectively or stopping. Common issues include:
– Incorrect settings, such as the fan being set to “ON” instead of “AUTO,” which circulates warm air.
– Poor calibration or a faulty sensor that fails to signal the AC to cool properly.
A smart thermostat is handy in hot climates like Los Angeles, allowing for cooling schedules, remote adjustments, and energy monitoring to manage costs.
AC systems circulate refrigerant through the compressor. If the compressor fails, the system won’t cool the air effectively. The problem here is a more serious issue and can often result in the entire AC unit needing to be replaced.
A compressor failure is a major repair requiring HVAC professionals’ expertise. If your AC is running but not cooling, and you’ve ruled out other issues, a technician must inspect and potentially replace the compressor.
Given Los Angeles’ hot climate, compressors often work overtime during the peak summer months. Annual maintenance can prevent costly repairs and extend its life.
Your AC unit has a condensate drain that removes excess moisture from the air. Excess humidity can malfunction the system if this drain becomes clogged, reducing cooling efficiency. Additionally, you may notice that water pools around the unit.
Clear the condensate drain using a wet/dry vacuum to remove debris or buildup. If you’re uncomfortable doing this yourself, an HVAC technician can perform this service during a routine maintenance check.
A clogged condensate drain is common during the humid months in Los Angeles. Keep the drain clear to ensure your AC runs efficiently during the summer.
Leaky or damaged ductwork, common in older Los Angeles County homes, allows cool air to escape, causing your AC to work harder and deliver insufficient cooling.
In Los Angeles County, where older homes and high temperatures are common, maintaining ductwork is essential for comfort and energy efficiency. Professional sealing ensures effective cooling in larger homes with long duct runs.
As the world becomes more eco-conscious, many homeowners seek energy-efficient upgrades like:
While some AC issues can be tackled with DIY solutions, specific problems demand professional expertise. Here’s when to call Affordable Heating and Air:
If your AC isn’t blowing cold air, or you’ve been wondering why your AC isn’t cooling or blowing hot air, don’t hesitate to ask for assistance.
Contact Affordable Heating and Air for quick, affordable solutions tailored to your needs. Your comfort is just a call away!
For more information, or to schedule an AC inspection or affordable repair, call us today at 818-722-1332. Stay cool and comfortable year-round with our fast, reliable service and guaranteed satisfaction.
We’re committed to providing top-notch HVAC services in Los Angeles County. With our years of experience, certification, and dedication to customer satisfaction, you can trust us to keep your cooling systems in peak condition.
Contact us today and let our expert team handle all your air conditioning needs.
