Hi folks, Mike here. Let me tell you something I’ve learned the hard way: you can spend thousands on the best condenser, the best furnace, or even the latest thermostat—but if you let your A-Coil get dirty or neglected, your whole AC system suffers.
Your Goodman CHPTA horizontal cased coil is the workhorse inside your home that quietly keeps the cool air flowing. But like any workhorse, it needs a little TLC to run at peak performance.
In this guide, I’ll give you my step-by-step seasonal checklist for keeping your A-Coil clean, efficient, and long-lasting.
🌀 1. Why Coil Maintenance Matters
Think of the A-Coil (also called the evaporator coil) as the indoor half of your AC system. It’s where warm air from your house passes over chilled refrigerant, dropping the temperature of the air before it’s blown back into your living spaces.
Now imagine what happens if that coil is clogged with dust, pet hair, or pollen:
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Airflow gets choked.
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Cooling efficiency drops.
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The coil can freeze solid.
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Your compressor works harder and may fail prematurely.
According to Energy.gov, dirty coils can increase energy consumption by up to 30%. That’s money right out of your pocket.
Mike’s take: “Keeping your coil clean is like changing the oil in your car. It’s not glamorous, but it’s what makes everything else last.”
📦 2. Before You Start: Tools & Safety
Before you go poking around your coil cabinet, let’s cover the basics.
Tools You’ll Need
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Flashlight 🔦 (to spot dirt, leaks, and damage)
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Soft brush 🖌️ (for dust removal)
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Fin comb 🪚 (to straighten bent fins)
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Wet/dry shop vacuum 🧹 (to suck up debris)
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Mild coil cleaner 🧴 (non-acidic, safe for aluminum/copper)
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Screwdriver or nut driver 🪛 (to open cabinet panels)
Safety Gear
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Gloves 🧤 (coil fins are sharp)
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Safety glasses 👓
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Dust mask 😷
Safety First!
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Turn off power at the breaker before working inside your air handler or coil cabinet.
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If you need to disconnect refrigerant lines or open sealed sections, stop. That’s a job for an EPA-certified technician (EPA Section 608).
🗓 3. Seasonal Maintenance Checklist
Keeping your coil running smooth is all about year-round habits. Here’s my breakdown by season.
🌸 Spring (Pre-Cooling Season)
Spring is when you prep your system before the heavy summer load.
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Inspect the Coil Cabinet – Look for dust, rust, or moisture.
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Clean the Coil Surface – Spray with a foaming coil cleaner, let it soak, then rinse with water.
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Check the Condensate Drain Pan & Lines – Make sure water flows freely. A clogged drain can overflow and ruin ceilings.
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Test the Drain with a Cup of Water – Better to find a clog now than in July.
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Inspect Insulation – The suction line insulation should be intact to prevent energy loss.
📖 Source: HVAC.com – Evaporator Coil Maintenance
☀️ Summer (Peak Cooling Season)
Summer is when your coil works the hardest.
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Monitor System Performance – If airflow feels weak, check your filter and coil.
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Watch for Ice Buildup – Ice on the coil means low airflow or refrigerant issues.
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Check Humidity Levels – If your home feels muggy, the coil may be dirty or oversized.
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Listen for Strange Sounds – Bubbling or hissing can mean refrigerant leaks.
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Verify Drain Flow – Algae loves to clog drain lines in humid weather.
📖 Source: Carrier – Why Coil Maintenance Matters
🍂 Fall (Post-Cooling Season)
After the cooling season ends, it’s time for a little post-game cleanup.
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Wipe Down the Coil and Cabinet – Remove dust, pollen, or debris.
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Inspect Coil Fins – Use a fin comb to straighten bent fins for better airflow.
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Replace Filters – Go into heating season with a fresh one.
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Look for Leaks or Corrosion – Early detection saves big money.
📖 Source: HVAC Maintenance Guide
❄️ Winter (Off-Season)
In many homes, the coil sits idle during winter. Don’t ignore it.
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Seal the Cabinet – Prevent rodents or pests from nesting inside.
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Check for Moisture – Attics and crawlspaces can be damp; make sure your coil is dry.
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Vacuum Surrounding Area – Dust buildup in winter settles on coils and gets pulled in when spring hits.
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Quick Visual Inspection – Even if not in use, problems can start quietly.
Mike’s reminder: “Just because it’s not running doesn’t mean it doesn’t need attention.”
💧 4. Condensate Drain & Pan Care
The condensate system is one of the most overlooked parts of coil maintenance.
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Flush the Line – I run a cup of vinegar through mine every spring. Keeps algae away.
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Install a Float Switch – This little sensor shuts down the system if the drain backs up. Saved me from a ceiling repair once!
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Check Pan Condition – Rusty or cracked pans = leaks waiting to happen.
📖 Source: ACHR News – Preventing Condensate Drain Problems
🔎 5. Air Filter & Airflow Checks
The #1 cause of coil issues I’ve seen? Dirty filters.
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Replace filters every 1–3 months, depending on pets and dust.
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Choose the right MERV rating – higher isn’t always better. A too-restrictive filter can choke airflow and freeze the coil.
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Check return vents to make sure they’re not blocked by furniture.
📖 Source: ASHRAE – Air Filtration Guidance
🛠 6. Professional Maintenance: When to Call a Pro
Some things are best left to licensed HVAC techs. Schedule annual maintenance for:
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Deep coil cleaning with professional-grade chemicals.
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Checking refrigerant charge and adjusting if needed.
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Inspecting the TXV operation (thermal expansion valve).
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Leak detection if performance drops.
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Measuring superheat and subcooling to confirm proper operation.
📖 Source: ACCA – HVAC Maintenance Standards
⚠️ 7. Common Mistakes to Avoid
Here are mistakes I’ve made—or seen others make—that you should avoid:
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Using harsh cleaners – Acidic cleaners eat away at fins. Always use coil-safe sprays.
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Forgetting to shut off power – That blower can kick on unexpectedly.
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Ignoring small leaks – Little drips become big ceiling stains.
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Letting the coil freeze over – Don’t just thaw it out; find the root cause.
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Skipping maintenance – Out of sight, out of mind? Not with your coil.
✅ 8. Mike’s Final Takeaways
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A clean coil saves money, reduces breakdowns, and improves comfort.
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Most coil maintenance (inspection, cleaning, drain flushing) is DIY-friendly.
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Refrigerant checks and deep cleanings = call a pro.
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Seasonal checkups prevent 90% of common coil problems.
Mike’s bottom line: “Take care of your coil, and it’ll take care of you every summer. Ignore it, and you’ll be calling me—or worse, an expensive repair guy—when it’s 95° outside.”
In the next topic we will know more about: Troubleshooting Guide: What to Do If Your A-Coil Freezes or Leaks
