5 HVAC Maintenance Mistakes That Can Lead to Costly Repairs
When it comes to keeping your fleet comfortable year-round, your HVAC system plays a critical role. From sweltering summers to frozen winters, a well-maintained HVAC system ensures your drivers can stay focused, safe, and productive.
Most major HVAC system failures aren’t because of rare part defects. They’re the result of simple, avoidable maintenance mistakes, and here are 5 of the most common ones you need to be aware of!
Mistake 1: Neglecting Filter Replacements
Over time, clogged filters restrict airflow, causing the system to work harder and reduce its overall efficiency. It can even lead to compressor failure, which is a significant expense.
You should replace or clean HVAC filters on a regular schedule—typically every 15,000 to 30,000 miles for heavy-duty trucks, but always refer to your OEM guidelines. Skipping this basic task puts extra strain on the blower motor and compromises cabin air quality. No one wants to breathe dust and diesel.
Mistake 2: Overlooking Refrigerant Leaks
Even a small refrigerant leak can slowly deplete the system, leading to poor cooling performance, increased fuel consumption (and who can afford that with today's diesel prices?), and eventually, full-system failure. Worse yet, running low on refrigerant often leads to compressor damage, and replacing that part isn’t cheap.
A technician should check refrigerant levels during scheduled inspections. If the system is low, don’t just “top it off.” Locate the leak, seal it, and verify the repair with a thorough pressure test.
Mistake 2: Ignoring Electrical Issues
HVAC systems aren’t just hoses and vents—they rely heavily on electrical connections, sensors, and control modules. Frayed wires, corroded connectors, or faulty thermostats can cause intermittent failures that are challenging to diagnose but can be disastrous in terms of lost productivity and downtime.
Let’s face it: when a sensor goes haywire, your A/C can kick on full blast in winter—or not at all in the middle of a heatwave. This can lead to increased driver fatigue, which is responsible for approximately 91,000 crashes each year in the US alone. Ensure your HVAC electrical system is included in your routine preventive maintenance checklist.
Mistake 4: Failing to Inspect the Blower Motor
Think of the blower motor as the muscle behind your cabin airflow. If it’s weak or failing, you won’t get sufficient heating or cooling, no matter how well the rest of your system works. What starts as a faint whining noise or weak airflow can quickly become a no-blow scenario.
Often, blowers fail due to debris, worn-out bearings, or burnt-out resistors. Checking this component is quick and can be done during routine PM service. Don’t wait until the cab turns into a sauna—or an icebox.
Mistake 5: Skipping Seasonal Maintenance
New England weather isn’t kind to HVAC systems. Hot, humid summers and icy winters mean your system has to shift gears fast. If you're not doing seasonal inspections, you're inviting trouble.
Each spring and fall, inspect the system for pressure balance, refrigerant charge, compressor function, and heater core performance. Addressing minor wear before the season flips saves you the pain of an HVAC meltdown when you need it most.
Final Thoughts
In the world of heavy-duty maintenance, preventive HVAC care is low-hanging fruit. It’s relatively quick, doesn’t require exotic parts, and can prevent massive repair bills and driver complaints. By avoiding these five common HVAC maintenance mistakes, you’re not just saving money—you’re building a more reliable, driver-friendly fleet.
Need help building a seasonal HVAC checklist for your trucks? Let’s get one put together before the weather catches you off guard.
