AC Not Cooling? A New Jersey Homeowner’s Air Conditioner Troubleshooting Guide (2025)
An air conditioner that runs but no longer cools is usually experiencing an airflow, refrigerant, electrical, or thermostat-related issue. In New Jersey homes, humidity and older ductwork can make cooling problems more common and more noticeable.
Quick Checklist Before You Call for Service
- Is the outdoor condenser running?
- Is the air filter clogged?
- Is warm air blowing from the vents?
- Is there ice on the refrigerant lines?
- Is the thermostat set to “Cool” and on Auto?
- Is the outdoor unit blocked by leaves or debris?
- Are upstairs rooms noticeably hotter than downstairs?
Common Causes of AC Not Cooling in New Jersey Homes
Dirty Air Filter
A clogged filter restricts airflow and can cause the evaporator coil to freeze. During New Jersey’s summer months, filters clog faster due to pollen and humidity. Replace the filter with a MERV 8–11 filter and check again after one hour of runtime.
Low Refrigerant (Leak)
Low refrigerant is common in older units found in Woodbridge, Edison, and surrounding areas. Symptoms include warm air, hissing noises, and frozen refrigerant lines. Low refrigerant almost always indicates a leak and requires professional repair.
Frozen Evaporator Coil
A frozen coil is usually caused by airflow restriction, dirty coils, or low refrigerant. Turn the system off, set the fan to “ON,” allow the coil to thaw, replace the filter, and restart the system. If it refreezes, service is required.
Outdoor Unit Not Operating
If the outdoor unit is silent or the fan isn’t spinning, the cause may be a bad capacitor, tripped breaker, damaged contactor, or an overheated compressor. If the unit hums but the fan doesn’t turn, this is often a sign of a failing capacitor.
Thermostat Issues
Incorrect settings, dead batteries, or poor placement can cause cooling problems. Ensure the thermostat is in “Cool” mode, set to Auto (not On), and away from heat sources or direct sunlight.
Ductwork Problems
Many older New Jersey homes have undersized or leaky ductwork. Signs include hot and cold spots, weak airflow, and uneven cooling between floors. This often requires duct balancing or repair.
What Temp Control Technicians Check
- Safety check of electrical and system components
- Airflow evaluation (filter, blower motor, evaporator coil, duct pressure)
- Refrigerant testing (pressure, superheat, subcooling, leak detection)
- Outdoor system inspection (coil, fan motor, compressor, electrical parts)
- Efficiency testing, including temperature split and humidity level review
When to Call for Service
Call for professional service if:
- The system is running but blowing warm air
- Ice returns after thawing
- The outdoor unit cycles rapidly
- You hear bubbling or hissing sounds from refrigerant lines
- Your home cannot cool below 76–80°F
- The breaker repeatedly trips
How to Prevent Cooling Problems
- Replace filters every 60 days (every 30 days in summer)
- Schedule annual tune-ups
- Keep shrubs and debris at least 2–3 feet from the outdoor unit
- Clean the outdoor coil at least once per season
- Have ductwork inspected in multi-level homes
Service Area
Temp Control provides HVAC repair and installation in Woodbridge, Edison, Perth Amboy, Colonia, Fords, Iselin, Avenel, Carteret, Clark, Rahway, Linden, Elizabeth, and surrounding New Jersey communities.
Get Fast AC Repair in New Jersey
Temp Control offers same-day AC repair in Woodbridge and surrounding New Jersey towns. Our certified technicians diagnose cooling problems quickly and get your home comfortable again.
Call Temp Control at (732) 218-8400 for fast, reliable AC service in New Jersey.