Commercial HVAC & Refrigeration Troubleshooting Guide (DFW Businesses)
Commercial HVAC and refrigeration systems work harder and run longer than residential equipment, especially in the demanding climate of the Dallas–Fort Worth Metroplex. When cooling, heating, or refrigeration equipment fails, it can disrupt operations, damage inventory, and create safety concerns. This guide provides practical, safe troubleshooting steps your team can perform before calling for service.
1. Verify Thermostat or BAS Settings
Commercial buildings often use programmable thermostats or building automation systems (BAS).
What to check:
- Ensure the system is set to Cool, Heat, or Auto as needed.
- Confirm schedules aren’t overriding manual settings.
- Check for locked or restricted access modes.
- Replace batteries on non‑hardwired thermostats.
Common DFW Issues: incorrect BAS schedules after power outages, thermostat lockouts, and misconfigured setpoints.
2. Inspect Air Filters and Return Airflow
Commercial units clog faster due to higher foot traffic and longer run times.
What to do:
- Check rooftop unit (RTU) filters monthly.
- Replace dirty or collapsed filters immediately.
- Ensure return grilles aren’t blocked by boxes, shelving, or equipment.
Why it matters: restricted airflow causes coil freezing, overheating, and high energy usage — common in DFW summers.
3. Check Breakers, Disconnects, and Fuses
Commercial HVAC and refrigeration equipment often has multiple power points.
What to check:
- Main electrical panel breakers
- Rooftop unit disconnects
- Line‑side fuses
- Walk‑in cooler/freezer disconnects
If a breaker trips more than once, stop troubleshooting and call a technician.
4. Inspect Rooftop Units (RTUs)
RTUs are exposed to extreme Texas heat, hail, and debris.
What to do:
- Ensure condenser fans are running.
- Check for debris blocking coils.
- Listen for unusual noises (grinding, buzzing, rattling).
- Verify economizer dampers aren’t stuck open.
Common DFW Issues: hail‑damaged coils, clogged condenser fins, failed fan motors, and stuck economizers.
5. Check for Frozen Evaporator Coils
Commercial AC systems freeze for the same reasons as residential — but the impact is greater.
Signs:
- Ice on copper lines
- Water dripping from RTU or air handler
- Weak airflow
What to do:
- Turn system OFF
- Turn fan ON
- Replace filters
- Ensure supply/return vents are open
If freezing returns, it may indicate low refrigerant or airflow issues.
6. Inspect Walk‑In Coolers & Freezers
Refrigeration failures can lead to product loss within hours.
What to check:
- Door seals and hinges
- Evaporator fans running
- Ice buildup on coils
- Temperature setpoints
- Clear airflow inside the box
Common DFW Issues: dirty condenser coils, iced evaporators, failed fan motors, and blocked airflow from overloaded shelves.
7. Check Refrigeration Condenser Units
Most walk‑ins have outdoor condensers exposed to heat and debris.
What to do:
- Clear grass, trash, and grease buildup
- Ensure fans are spinning
- Listen for loud or abnormal noises
- Check for oil spots indicating refrigerant leaks
High ambient temperatures in DFW often cause high‑pressure lockouts.
8. Inspect Ice Machines
Ice machines are sensitive to water quality and airflow.
What to check:
- Water supply turned on
- Filters not clogged
- Condenser coils clean
- Bin switch not stuck
- Machine not pushed against the wall
Common DFW Issues: scale buildup, dirty filters, and overheated condensers in small kitchens.
9. Check Drain Lines & Pans
Commercial HVAC and refrigeration systems produce significant condensation.
What to do:
- Ensure drain lines are not clogged
- Clear algae with a wet/dry vacuum
- Check for overflowing pans
- Verify float switches are not tripped
High humidity in DFW makes drain clogs extremely common.
10. Inspect Evaporator Fans
If the system is running but not cooling, the evaporator fan may be the issue.
What to check:
- Fan blades spinning freely
- No ice blocking the fan
- No burnt smell from the motor
- Fan cycling properly
11. Check for Airflow Obstructions
Commercial spaces often unintentionally block airflow.
Look for:
- Boxes stacked in front of vents
- Shelving blocking returns
- Ceiling tiles out of place
- Closed fire dampers
12. Verify Temperature Setpoints
Incorrect setpoints can mimic equipment failure.
Recommended commercial settings:
- Dining areas: 70–74°F
- Kitchens: 72–76°F
- Offices: 70–73°F
- Walk‑in coolers: 34–38°F
- Walk‑in freezers: –5 to 0°F
13. Inspect Belts and Motors
RTUs often fail due to worn belts or seized motors.
What to check:
- Belt tension
- Cracks or fraying
- Motor noise
- Motor overheating
14. Look for Refrigerant Issues
Signs of low refrigerant include:
- Long run times
- Warm supply air
- Ice on lines
- High energy bills
Only licensed technicians can handle refrigerant, but identifying symptoms helps prevent downtime.
15. When to Stop Troubleshooting
Stop and call a commercial HVAC/R technician if you notice:
- Repeated breaker trips
- Burning smells
- Heavy ice buildup
- Loud grinding or screeching
- Rapid temperature rise in coolers/freezers
- Water leaking into occupied spaces
Still need help? Call us for 24/7 emergency service!
We provide commercial HVAC and refrigeration service across the Dallas–Fort Worth Metroplex, including Dallas, Fort Worth, Arlington, Irving, Grand Prairie, Mesquite, Garland, Richardson, Plano, Frisco, McKinney, Denton, Carrollton, Lewisville, Hurst, Euless, Bedford, Mansfield, Burleson, Keller, Southlake, Grapevine, Coppell, Allen, and surrounding North Texas areas. Whether you need rooftop unit repair in Dallas, walk‑in cooler service in Fort Worth, ice machine repair in Arlington, commercial refrigeration troubleshooting in Irving, or emergency HVAC repair near me anywhere in DFW, our licensed technicians are ready to keep your business running smoothly.