Introduction
Hey, Mike Sanders here.
If you’ve invested in a 5-ton R-32 AC and gas furnace system, you’re well-equipped for year-round comfort — especially for larger homes. But no matter how high-quality the system, problems can pop up. Understanding what’s normal and what’s a warning sign can save you time, money, and hassle.
In this guide, I’m going to walk you through some of the most common issues I see with 5-ton R-32 systems and how to troubleshoot them. I’ll also highlight when it’s time to call a professional — because some fixes require specialized tools and training, especially handling R-32 refrigerant safely.
1. Airflow Problems: Uneven Cooling or Heating
Common Symptoms
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Certain rooms feel too hot or cold
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Air vents feel weak or no airflow at all
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Increased energy bills due to inefficient heating/cooling
Possible Causes and Fixes
Blocked or Dirty Air Filters
Dirty filters reduce airflow and force your system to work harder. Check and replace filters every 1-3 months.
Duct Leaks or Poor Duct Design
Leaks or disconnected ducts reduce airflow to specific rooms. Inspect visible ducts for damage or disconnected sections. Professional duct testing and sealing may be required.
Closed or Obstructed Vents
Make sure all vents are open and unobstructed by furniture or curtains.
Improperly Sized Ducts
If your ductwork wasn’t sized properly for a 5-ton system, some rooms may not get enough airflow. This is a bigger issue requiring an HVAC professional.
💡 More info: Learn about duct design and sealing best practices from the ENERGY STAR duct sealing guide.
2. Refrigerant Issues: Leaks and Low Charge
Symptoms
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AC is blowing warm air or not cooling well
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Ice buildup on refrigerant lines or evaporator coil
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Higher energy bills and compressor running continuously
What’s Happening
R-32 refrigerant leaks are less common than older refrigerants, but when leaks occur, the system’s cooling efficiency plummets. Since R-32 is mildly flammable, handling and repair should be done by certified technicians.
Troubleshooting Steps
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Visually inspect refrigerant lines for oil residue or damage (signs of leaks)
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Check for ice buildup on refrigerant lines (may indicate low refrigerant or airflow issues)
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Have a certified pro perform a leak test and recharge with R-32 refrigerant if needed
Never try to add refrigerant yourself; R-32 handling requires special certification under EPA Section 608 regulations.
💡 More info: The EPA details refrigerant handling requirements on their Section 608 Refrigerant page.
3. Compressor Issues: Short Cycling or Failure
Symptoms
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AC cycles on and off frequently (short cycling)
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Compressor won’t start or is noisy
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Home never reaches desired temperature
Causes and Remedies
Oversized System
If your 5-ton system is too large for your home, it may short cycle. This reduces efficiency and stresses components. Proper Manual J load calculation can prevent this.
Dirty Coils or Filters
Dirty condenser or evaporator coils reduce heat exchange, causing compressor stress. Clean coils and filters regularly.
Electrical Issues
Wiring problems or a failing capacitor can prevent the compressor from starting properly.
Refrigerant Problems
Low refrigerant causes the compressor to overheat and shut down prematurely.
If your compressor is failing or making loud noises like grinding or humming, call a professional immediately. Compressor replacement is expensive and complex.
💡 More info: The HVAC School blog offers deep dives into compressor troubleshooting.
4. Furnace Ignition and Heating Problems
Symptoms
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Furnace won’t light or keeps shutting off
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Pilot light won’t stay lit (for older models)
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Furnace makes strange noises or smells
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No heat or insufficient heat
Causes and Fixes
Thermocouple or Igniter Failure
In older furnaces with pilot lights, the thermocouple can wear out. Newer furnaces have electronic igniters that may fail. Replacing these parts usually restores ignition.
Dirty or Clogged Burners
Burners clogged with soot or debris cause incomplete combustion and ignition failure. Annual cleaning is critical.
Faulty Flame Sensor
A dirty or failing flame sensor can cause the furnace to shut off shortly after lighting. Cleaning or replacing the sensor solves this.
Gas Supply Issues
Make sure your gas valve is open and gas supply is uninterrupted.
If you smell gas or suspect a leak, leave the area immediately and call your utility company or emergency services.
💡 More info: The Consumer Product Safety Commission (CPSC) explains furnace safety and carbon monoxide risks.
5. Thermostat Problems
Symptoms
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System won’t turn on or off
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Temperature doesn’t match thermostat setting
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Erratic system cycling
Troubleshooting
Check Batteries
If you have a battery-powered thermostat, replace batteries regularly.
Thermostat Placement
Avoid placing thermostats near heat sources, direct sunlight, or drafts.
Recalibrate or Replace
Older thermostats may need recalibration or replacement, especially if erratic behavior persists.
Smart Thermostat Connectivity Issues
For WiFi thermostats, ensure a strong network connection and updated firmware.
6. Strange Noises and Odors
Noises
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Rattling: Loose parts or debris in blower or ducts
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Grinding: Motor or compressor issues — call a pro ASAP
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Hissing: Possible refrigerant leak or air escaping
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Banging: Duct expansion or delayed ignition in furnace
Odors
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Burning Smell: Electrical issues or overheating components
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Rotten Eggs: Gas leak — evacuate immediately and call utility company
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Moldy/Musty: Mold in ducts or condensate drain
When to Call a Professional
While some minor issues like filter changes and thermostat resets you can handle yourself, many problems need certified HVAC technicians, especially with R-32 refrigerant systems. Call a pro if:
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You suspect a refrigerant leak or need recharging
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The compressor or furnace won’t start or runs noisily
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You smell gas or carbon monoxide
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You notice water leaks around your furnace or AC
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Electrical components need inspection or replacement
Pro Tips to Avoid Issues
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Schedule annual professional maintenance visits — this is the best way to catch small problems before they become costly.
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Change filters regularly to protect your equipment.
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Keep your outdoor condenser unit clean and clear of debris.
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Use a programmable thermostat to reduce system stress and energy use.
Final Thoughts from Mike
Troubleshooting your 5-ton R-32 AC and furnace system can save you headaches and money, but always respect the complexity and safety concerns — especially with R-32 refrigerant and gas systems. When in doubt, reach out to a trusted HVAC professional who knows your equipment.
If you’re shopping for reliable 5-ton R-32 systems or need expert installation and service, check out The Furnace Outlet’s 5-ton R-32 AC and Furnace collection.
