Your HVAC system works quietly behind the scenes to keep your home comfortable. But when something goes wrong, it can throw off your entire day—especially during a hot Northern California summer or a damp winter morning. The good news? Most HVAC problems give you warning signs before they become costly breakdowns.
Here are five of the most common HVAC issues we see in homes across Concord, Napa, Berkeley, and beyond—and how you can catch them early.
1. Dirty or Clogged Air Filters
The problem:
Over time, air filters collect dust, pet hair, pollen, and other debris. A clogged filter restricts airflow and forces your HVAC system to work harder than it should.
How to spot it:
- Weak airflow from vents
- Higher energy bills
- More dust around your home
- Musty odors
What to do:
Check your filter every 30–60 days, especially during high-use months. If it’s visibly dirty, it’s time to replace it.
2. Thermostat Issues
The problem:
If your thermostat isn’t calibrated or functioning properly, your system may not turn on—or it might cycle on and off too frequently.
How to spot it:
- Room temperature doesn’t match the thermostat setting
- Short cycling (system turns off and on quickly)
- Thermostat screen is blank or unresponsive
What to do:
Try replacing the batteries first. If issues persist, your thermostat may need recalibration or replacement—especially if it’s outdated.Upgrade Tip: A smart thermostat can improve comfort and energy savings, especially in variable Northern California climates.
3. Refrigerant Leaks
The problem:
Your AC relies on refrigerant to cool your home. If there’s a leak, your system won’t cool effectively—and it can damage the compressor if ignored.
How to spot it:
- Warm air blowing from vents
- Hissing or bubbling noises near the outdoor unit
- Ice on the refrigerant line or evaporator coil
- Rising energy bills
What to do:
This is not a DIY fix. Call a licensed HVAC technician to locate the leak, repair it, and recharge the refrigerant to manufacturer levels.
4. Dirty or Frozen Evaporator Coils
The problem:
Evaporator coils absorb heat from your home’s air. When they get coated in dust or freeze up, airflow is blocked—and your AC stops working properly.
How to spot it:
- Little to no cool air from vents
- Unusual dripping or condensation near the unit
- AC runs constantly without lowering the temperature
- Ice buildup on visible coils or refrigerant lines
What to do:
Turn off the system and let it thaw. Then call a professional for a proper cleaning and system inspection.
5. Electrical or Capacitor Failures
The problem:
HVAC systems rely on several electrical components to start and run. A failed capacitor or corroded wiring can cause the system to shut down unexpectedly.
How to spot it:
- Clicking sounds when trying to start
- The system doesn’t turn on at all
- Frequent breaker trips
- Burning smell near the unit
What to do:
Do not attempt electrical repairs yourself. A licensed technician can safely test components and restore proper operation.
Why Early Detection Matters
Catching these issues early:
- Prevents costly repairs or system failure
- Improves energy efficiency
- Extends the lifespan of your equipment
- Keeps your family comfortable and safe
Routine inspections and seasonal maintenance are your best defense. Our team at Jazz Heating, Air Conditioning and Plumbing knows what to look for—and how to fix it before it becomes a major problem.
Need a Tune-Up or Troubleshooting Visit?
Whether you’ve noticed strange sounds, rising utility bills, or airflow issues, don’t wait for a full system shutdown. Our experienced HVAC techs will diagnose and fix the issue quickly—keeping your home running smoothly.
Call Jazz Heating, Air Conditioning and Plumbing today to schedule your HVAC inspection or maintenance visit.