Jake Here!
When it comes to HVAC installs, precision matters—especially with modern refrigerants like R-32. If you’re working with the Goodman 3 Ton 14.5 SEER2 R-32 System (GLXS4BA3610 + AMST36CU1300), you already know this system offers high performance and energy efficiency. But even the best equipment can underperform—or fail entirely—if installed incorrectly.
Whether you're a licensed installer or a knowledgeable homeowner working with a technician, avoiding these seven common installation mistakes will help your new system live up to its full potential.
1. Skipping the Proper R-32 Safety Protocols
R-32 is a low-GWP, mildly flammable A2L refrigerant. It’s not dangerous when handled correctly, but it requires careful attention to safety during installation.
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Mistake: Treating R-32 like R-410A without reviewing the A2L handling guidelines.
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Fix: Follow ASHRAE safety standards for refrigerant handling. Use leak detectors rated for A2L refrigerants and make sure your installation area has proper ventilation.
2. Forgetting to Properly Evacuate the System
This is one of the biggest issues we see. Moisture and air left in the system lead to:
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Reduced efficiency
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Acid formation inside the compressor
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Long-term mechanical failure
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Mistake: Skipping vacuum or only pulling a partial vacuum before charging.
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Fix: Pull a deep vacuum to 500 microns or lower using a micron gauge, and make sure it holds. No exceptions.
3. Using Incorrect Line Set Sizes or Lengths
The Goodman GLXS4BA3610 + AMST36CU1300 system is designed for specific line set sizes and distances.
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Mistake: Using an existing line set that’s the wrong diameter or too long/short.
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Fix: Follow the system engineering guidelines—typically 3/4" suction and 3/8" liquid lines for this 3-ton model, with a recommended max of 50 feet. Check HVAC School’s line sizing chart to verify.
4. Not Adjusting for Air Handler Static Pressure
The AMST36CU1300 air handler includes a multi-speed ECM motor that’s designed to handle varying duct pressures—but only if you match it correctly.
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Mistake: Installing with ductwork that exceeds the max ESP (External Static Pressure) rating, causing airflow problems.
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Fix: Measure total ESP after duct connection and verify airflow performance using Goodman’s airflow charts in the spec sheet. Oversized returns and sealed ducts help.
5. Incorrect Electrical Wiring or Breaker Sizing
It seems basic, but even seasoned techs can misjudge the amp draw of R-32 units, especially if switching from older R-410A systems.
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Mistake: Undersizing or oversizing the breaker and wiring for the condenser and air handler.
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Fix: Always match the MCA (Minimum Circuit Ampacity) and MOCP (Maximum Overcurrent Protection) ratings found on the unit’s data tag. Check out this NEC HVAC wiring guide for a refresher.
6. Charging by Pressure Instead of Weight
Unlike R-410A, R-32 requires precision charging by weight—not just reading pressure gauges.
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Mistake: Using old-school superheat/subcooling pressure methods to guess the charge.
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Fix: Always charge by factory-specified weight using a scale. For line sets outside the standard range, adjust using Goodman’s refrigerant charge adjustment chart.
For R-32 charging tips, check out this article from ARC.
7. Skipping a Final System Leak Check
Even if you used new flares or brazed correctly, a system without a final leak check is a liability waiting to happen.
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Mistake: Relying on a single vacuum test without a secondary leak check.
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Fix: Use an A2L-compatible electronic leak detector and bubble test every connection point. Don't forget the Schrader valves.
Final Word: A Smooth Install Starts with the Right System
Avoiding installation mistakes isn't just about following directions—it's about respecting the performance potential of high-efficiency equipment like the Goodman GLXS4BA3610 + AMST36CU1300. Whether it’s your first time working with R-32 or you’re transitioning from R-410A, learning the nuances of this new refrigerant ensures your installation runs safer and smoother.
👉 Ready to upgrade? You can order the complete Goodman 3 Ton 14.5 SEER2 R-32 System here and install with confidence.
Worrying about wiring your system wrong? Visit: How to Properly Connect the Thermostat to Your Goodman GLXS4BA3610 + AMST36CU1300.
Until next time,
- Samantha, Home Comfort Advisor
