7 Urgent Signs Your AC Needs Immediate Repair

When your AC struggles, it’s easy to brush it off as a minor annoyance. But some problems are more than inconvenient — they’re red flags that can damage your system, skyrocket repair costs, or even put your home at risk. Knowing the difference can save you from a sudden breakdown and keep your family safe.

Here are 7 urgent signs your AC needs immediate repair — and why they matter.

1. Refrigerant Leaks

Look for hissing noises, ice buildup on the evaporator coils, or puddles around your indoor or outdoor unit—these often signal a refrigerant leak.

Refrigerant is the core of your AC’s cooling process, absorbing heat from indoor air and releasing it outside. Low levels force the system to work harder, reducing efficiency and risking serious damage.

Why Refrigerant Is Critical

• It drives the cooling cycle by absorbing and releasing heat.

• Low refrigerant overworks the compressor, leading to potential failure.

• Even small leaks reduce efficiency and make your AC work harder, raising energy bills.

Health and Safety Risks

Refrigerants can be toxic. Exposure may cause dizziness, headaches, nausea, or, in rare cases, more severe effects like asphyxiation in confined spaces. Leaks also harm the environment by contributing to ozone depletion.

System Damage Over Time

Untreated leaks can freeze coils, cause compressor burnout, and necessitate a full system replacement. The EPA requires leaks exceeding certain thresholds to be repaired within 30 days to minimize health and environmental risks.

Tip: Schedule annual AC maintenance to catch leaks early. A professional can safely check refrigerant levels and inspect for corrosion, which is common in coastal areas.

2. Electrical Burning Smells

A burning or smoky odor from your AC is never a good sign. It usually means something inside is overheating — such as wiring, the fan motor, or internal circuitry.

Common Causes of Burning Smells

• Frayed or worn wires that overheat and could spark.

• Overworked motors generating excess heat.

• Geckos, lizards, or insects sometimes crawl onto circuit boards or wires, causing shorts and burn damage.

Electrical issues aren’t just bad for your AC — they’re dangerous for your home. If you notice this smell, turn off your system immediately and call a technician. Continuing to run it can put your home at risk of fire.

Why It’s Dangerous

Electrical issues aren’t just bad for your AC — they’re dangerous for your home. According to the Electrical Safety Foundation International (ESFI), air conditioners, fans, and related equipment were involved in about 7,400 U.S. home structure fires in a single year, resulting in 29 civilian deaths, 249 injuries, and more than $200 million in property damage. [ESFI]

The U.S. Fire Administration has also found that roughly half of all AC fires start from short circuits inside the unit, with window and wall units being especially prone to these hazards. [USFA]

That means what starts as a faint burning smell could escalate quickly into a house fire.

If you notice this odor, shut off your system immediately and call a technician. Continuing to run it not only risks damaging your AC — it puts your home and family at serious risk.

3. Water Leaks or Drainage Backups

Puddles, drips, or standing water near your AC unit signal trouble. Beyond the mess, water can damage floors, walls, electrical components, and foster mold growth.

Common causes include a clogged condensate drain line or a broken pump. In humid environments, these issues escalate quickly, turning small leaks into major moisture problems within days.

Why Water Damage Spreads Fast in Humid Climates

Moisture in the air accelerates the damage caused by leaks. Humid conditions prevent water from evaporating, allowing it to seep deeper into walls and flooring. This not only increases the chance of mold growth but can also compromise wood, drywall, and insulation much faster than in drier climates.

4. Loud Grinding, Screeching, or Metal-on-Metal Noises

A soft hum is normal, but grinding, screeching, or metal-on-metal sounds are not. These noises often point to failing bearings, loose belts, or motor issues.

If ignored, the damage doesn’t stop at the motor — prolonged friction can also harm the blower wheel and connected components. Running the system under these conditions often turns a small repair into a major breakdown requiring urgent HVAC service.

5. Constant Tripping of the Breaker

If your AC keeps shutting down and flipping the breaker, don’t just reset and forget it. This means the system is pulling more power than it should.

Common causes include dirty coils, wiring shorts, or a failing compressor. Whatever the reason, repeated breaker trips aren’t just an inconvenience — they’re unsafe. You risk damaging the AC further and overloading your electrical system if the problem isn’t corrected.

6. Strong Musty or Moldy Odors

When you smell must or mildew every time the AC runs, it’s more than unpleasant — it means microbial growth is present in your system or ductwork. Prolonged neglect allows mold to spread, circulating spores throughout your home.

Health Risks of Mold in Your AC

Breathing mold-contaminated air can cause:

• Allergy flare-ups (sneezing, runny nose, itchy eyes)

• Respiratory irritation and coughing

• Worsened asthma or bronchial conditions

Studies confirm that indoor mold is linked with asthma attacks, coughing, and other respiratory issues [EPA; Lung Association]. Research on split AC units has also found fungal growth inside systems, which can aggravate allergies and asthma [ScienceDirect].

Mold inside your AC doesn’t just affect comfort — it directly impacts your family’s health. At this stage, only a professional cleaning and sanitization will solve the problem.

7. AC Won’t Turn On at All

An AC that won’t start — or turns on but immediately shuts down — usually points to a serious failure. Electrical issues, bad capacitors, or a seized compressor could all be to blame.

It may be tempting to keep trying, but forcing the system on can cause further damage. The safest step is to call an HVAC professional for a full inspection.

Don’t Wait — Act Fast to Protect Your System

These warning signs aren’t just minor inconveniences — they’re red flags that your AC could be headed for a costly breakdown or even create risks in your home. Acting quickly protects your comfort, your wallet, and your safety.

If you notice any of these issues, don’t ignore them. Shut your system down and call a licensed HVAC technician right away.

Call Craig’s to Get Your AC Done Right

Need fast AC repair or professional maintenance in Hawaii? Call Craig’s Air Conditioning today at (808) 682-0970 or schedule your service online — and get peace of mind knowing your system is in expert hands.