❄️ Introduction: Keeping Cool When Problems Strike
Your through-the-wall air conditioner is built to last for years, delivering powerful cooling and keeping you comfortable. But just like any hardworking appliance, it can run into hiccups — especially during long, hot summers. Whether your AC is blowing warm air, leaking water, or making strange noises, this guide will help you pinpoint the cause and take action.
And if you ever need to upgrade to a new unit, check out the efficient, eco-friendly models in our Through-the-Wall AC collection at The Furnace Outlet. But before you shop, let’s troubleshoot!
🔍 Common Problems & DIY Fixes
Here’s a round-up of the most common through-the-wall AC issues and Savvy Mavi’s tried-and-true solutions.
💨 1. AC Not Cooling Properly
Symptoms: Warm or lukewarm air coming from vents, AC running continuously without reaching the set temperature.
Possible causes:
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Clogged air filter
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Dirty condenser or evaporator coils
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Incorrect thermostat settings
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Refrigerant leak
Quick Fixes:
✅ Clean or replace the air filter — clogged filters block airflow and decrease cooling efficiency.
✅ Check thermostat settings — make sure it’s set to “Cool” and at the desired temperature.
✅ Inspect outside condenser fins — clean them with a gentle brush or hose spray.
✅ Keep blinds or curtains closed during the hottest part of the day to reduce heat gain.
If the issue persists, you may have a refrigerant leak. It’s illegal to handle refrigerants without a certification, so contact a pro technician. The EPA refrigerant safety page offers useful guidance on handling refrigerant properly.
💦 2. AC Leaking Water
Symptoms: Dripping water inside the room, damp walls or floor.
Possible causes:
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Clogged condensate drain
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Poor unit tilt or improper installation
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Ice melting inside the unit
Quick Fixes:
✅ Check the tilt — through-the-wall ACs must tilt slightly (about ¼ inch downward toward the outside) to allow proper drainage.
✅ Clear the drain hole — use a pipe cleaner or stiff wire to unclog.
✅ Clean the filter — restricted airflow can cause icing on the coils, which then melts and drips.
✅ Ensure all seals are tight — water can enter through gaps around the unit.
When installing new units, follow a proven Step-by-Step Installation Guide like the one at The Furnace Outlet’s blog, or check the U.S. Department of Energy’s Home Cooling Systems page for tips on proper sealing.
🧊 3. Ice Buildup on the Coils
Symptoms: Frost on indoor coils or ice visible on the unit.
Possible causes:
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Restricted airflow
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Low refrigerant
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Thermostat set too low
Quick Fixes:
✅ Clean or replace the air filter — good airflow is key to preventing ice.
✅ Allow the unit to thaw — switch off and let the ice melt completely before restarting.
✅ Check refrigerant levels — persistent icing may require a professional check.
You can also learn more about proper refrigerant handling and climate-friendly refrigerants like R-32 in this EPA refrigerant overview.
🔊 4. Loud Noises or Vibrations
Symptoms: Banging, rattling, or buzzing noises during operation.
Possible causes:
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Loose screws or panels
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Fan hitting debris
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Uneven mounting
Quick Fixes:
✅ Tighten all visible screws — loose parts cause excess vibration.
✅ Inspect the fan area — clear debris and straighten any bent fan blades carefully.
✅ Ensure the unit is level — use a level and shims to adjust.
✅ Add rubber pads or insulation around the unit to dampen noise.
If you continue to hear noises after these adjustments, a damaged compressor or motor could be the culprit — call an HVAC pro.
🕯️ 5. AC Won’t Turn On
Symptoms: No power, control panel dead.
Possible causes:
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Blown fuse or tripped breaker
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Faulty thermostat
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Bad wiring or electrical connections
Quick Fixes:
✅ Check the breaker box — reset any tripped breakers.
✅ Test the outlet — plug another appliance in to see if there’s power.
✅ Examine the power cord — look for frays or damage.
✅ Test the thermostat — set it lower and listen for a click.
If there’s still no power, an electrician or HVAC technician may need to inspect the unit. Consult the National Fire Protection Association’s guidelines to ensure all electrical work is up to code.
🧭 When to Call a Professional
While basic troubleshooting can resolve most minor AC issues, some problems require specialized tools and expertise — especially if refrigerant, compressors, or electrical components are involved. Contact a licensed technician if you:
❌ Hear grinding or hissing noises
❌ Smell burning plastic or wiring
❌ See water damage around the unit
❌ Experience repeated breaker trips
Investing in a pro service will often save you time and costly mistakes — and can help your unit last longer.
🧠 Savvy Mavi’s Yearly Tune-Up Tips
A quick annual checkup can catch problems before they become breakdowns.
✅ Clean the coils and fins
✅ Verify refrigerant charge
✅ Test thermostat accuracy
✅ Inspect seals and sleeves for drafts
✅ Lubricate fan motors if applicable
And remember — if your unit is more than 10 years old and repair costs are mounting, it might be more cost-effective to upgrade to a new, high-efficiency R-32 model. Shop our collection of Through-the-Wall ACs at The Furnace Outlet to find the perfect fit for your home.
🧰 Conclusion
Through-the-wall ACs offer fantastic cooling power and long-term value — as long as they’re properly maintained. Many common AC problems can be solved with a few simple troubleshooting steps. But if you hit a snag you can’t resolve, don’t hesitate to call in the professionals. With the right care, your unit will keep you cool for years to come.
And as always — if you ever need guidance choosing a new AC or need help comparing features like R-32 refrigerant and SEER ratings, Savvy Mavi and The Furnace Outlet team are here to help you make a smart, confident choice!
