Why Your AC Isn’t Cooling - Common Problems

April 10, 2019

If your air conditioner is running but your home is not cooling properly, something is preventing the system from removing heat effectively. During hot, humid Michigan summers, even small performance issues can quickly make your home uncomfortable.

For homeowners in the Downriver area, reliable cooling isn’t optional — it’s necessary.

Below are the most common mechanical causes.


Restricted Airflow

Air conditioners require proper airflow across the evaporator coil to transfer heat.

Restricted airflow can result from:

  • A clogged air filter
  • Blocked return vents
  • A dirty evaporator coil
  • Blower motor issues

When airflow is reduced, heat transfer decreases and cooling performance drops. In more severe cases, insufficient airflow can cause the evaporator coil temperature to fall below freezing, leading to ice formation.


Low Refrigerant (Indicates a Leak)

Air conditioning systems are sealed systems. Refrigerant does not get used up during normal operation.

If refrigerant levels are low, there is a leak in the system.

Low refrigerant reduces the system’s ability to absorb and move heat, which can result in:

  • Reduced cooling capacity
  • Extended run times
  • Ice forming on refrigerant lines or coils

Proper repair requires locating and repairing the leak before recharging the system.


Frozen Evaporator Coil

Ice formation on the indoor coil prevents proper heat transfer.

Common causes include:

  • Restricted airflow
  • Low refrigerant pressure
  • Extended operation during high outdoor temperatures


Turning the system off may allow the ice to melt temporarily, but the underlying cause must be corrected for normal operation to resume.


Electrical Component Failure

Air conditioners rely on electrical components to start and operate the compressor and fan motors.

Common electrical failures include:

  • Capacitor failure
  • Contactor failure
  • Loose or damaged wiring

If the compressor or outdoor fan does not start properly, the system will not cool effectively.

Electrical diagnosis requires proper testing equipment.


Thermostat Issues

Improper thermostat settings, dead batteries, or wiring problems can prevent the system from operating correctly.

If the thermostat does not send the correct signal, the air conditioner will not cycle properly.


When to Schedule Professional AC Service

If cooling performance does not improve after replacing the air filter and verifying thermostat settings, the issue likely involves refrigerant levels, airflow performance, or electrical components.

Accurate diagnosis requires:

  • Measuring refrigerant pressure
  • Checking temperature split between supply and return air
  • Testing capacitors and electrical components
  • Verifying airflow and blower operation

These procedures require specialized tools and training.


If your home in Allen Park or the surrounding Downriver communities is not cooling properly, a professional inspection is the safest next step. AC’s Heating and Cooling provides thorough AC diagnostics and repair services throughout Allen Park and nearby areas. Our team identifies the exact cause of the issue and recommends the appropriate repair — without unnecessary work or guesswork.


Contact AC’s Heating and Cooling today to schedule professional AC repair in Allen Park and restore reliable cooling performance in your home.

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