A/C Problems in the Summer Heat? Boulder’s Auto Pros Explain Why

You hop into your car on a scorching July afternoon in Boulder. The sun’s blazing, your seatbelt buckle could fry an egg, and the pavement’s radiating heat is like a stovetop. All you want is a blast of cold air. You crank the A/C—and instead, you get a gust of warm, stale air. Now you’re inching along Broadway, windows down, sweat dripping, stuck in traffic, and wondering, Why now?

You’re not alone. At Pellman’s Automotive, we hear from drivers every day during the summer who are dealing with air conditioning troubles—many of which might have been avoided with a little prevention or timely diagnostics. Maybe your AC isn’t as cool as it used to be? Find out why and get it checked now to ensure you stay comfortable with optimal cooling on those hot summer days.

Below, we answer the top questions Boulder drivers search when their system starts blowing warm air (or nothing at all)—so you can stay cool, comfortable, and confident on the road.

This is the #1 summer complaint we hear. The most common causes include:

• Low refrigerant due to leaks
• A faulty compressor or condenser
• A clogged expansion valve

Fix: A professional diagnostic will detect low pressure, faulty components, or blockages. At Pellman’s, we use precision tools to test your entire system before recommending repairs.

If your air conditioner cools while driving but blows warm at a stoplight, it may be due to:

• A weak A/C compressor
• Cooling fan failure
• Low refrigerant levels
  

Fix: We’ll observe the compressor function and inspect your cooling fans to ensure proper airflow during idle conditions.

Inconsistent cooling often points to:

• A clogged or dirty cabin air filter
• Low refrigerant
• Failing sensors or blend door actuators
  

Fix: We inspect your filter, test refrigerant pressure , and use diagnostics to check for electrical issues or actuator malfunctions.

DIY recharge kits exist, but they often:

• Mask the real issue (like a leak)
• Overcharging the system causes damage
• Fail to include proper lubricant or pressure testing
• Will increase the cost of a professional repair

Fix: We recommend professional A/C service to ensure safe, efficient operation and long-lasting performance. At Pellman’s, we perform thorough tests, leak checks, and recharges using the correct refrigerant for your make and model. More importantly, air conditioning issues aren’t just a problem for your vehicle—they’re harmful to the environment. Releasing refrigerant into the atmosphere contributes to damaging emissions, which is why preventing leaks is so important. Our MACS-certified technicians are trained to handle your A/C system safely, and we can reclaim, clean, and recycle refrigerant—something DIY kits can’t do. Trust us to keep your A/C performing optimally while protecting the environment.

Repairs can range from a simple recharge to a new compressor. Costs depend on:

• The type of refrigerant
• The component failing (compressor, condenser, etc.)
• Vehicle make and model
  

Fix: At Pellman’s, we believe in upfront pricing and honest diagnostics. We thoroughly inspect and properly diagnose your vehicle before providing a cost to fix it—no upselling, just clear answers and transparent pricing.

Hissing may be normal during system pressure changes, but clicking, grinding, or buzzing can signal:

• Compressor clutch issues
• Loose components
• Debris in the blower motor
  

Fix: We’ll inspect belts, clutches, and internal parts to catch issues before they become major repairs.

A moldy or musty smell likely comes from:

• Mold in the evaporator core
• Dirty cabin air filters
• Moisture buildup
• Using the recirc button will increase the possibility of this condition. We recommend using the fresh air setting primarily.

Fix: We can disinfect your air conditioning system , replace your cabin filter, and improve airflow for fresher air every time you turn the key.

Your AC system is responsible for defrosting in winter, so it’s crucial to keep it operational year-round.

• Run your air conditioner weekly for 5 minutes year-round
• Replace the cabin air filter annually
• Check out our Seasonal Specials for deals on inspections and A/C service !
• Use the fresh air mode as often as possible

Whether you’re prepping for a road trip or just tired of sweating through your commute, Pellman’s Automotive has the tools, training, and care to get your A/C back to peak performance. We’re proud to be Boulder’s go-to automotive air conditioning shop, trusted by locals for over 30 years. Schedule your air conditioning inspection today and enjoy summer in cool comfort—because you deserve a car that works as hard as you do.