PTAC Maintenance Tips: How to Check for Refrigerant Leaks Before Major Damage

Key Takeaways

• Leaks lower cooling, raise bills, harm equipment.

• Check visually, listen, use bubble test.

• Call a pro for no cooling, loud hissing, wiring issues.

• Wear gloves, goggles, work in fresh air, cut power.

• See: The Furnace Outlet • HVAC Tips blog • PTAC heat pumps.

Why this matters: a simple problem with big costs 

A PTAC that’s low on refrigerant has to work harder to move heat. That means rooms don’t cool, humidity climbs, and energy bills rise. For hotels, apartments, and campus housing, this shows up as hot rooms and service calls. For homeowners, it’s frustration and wasted money. You’re here for PTAC maintenance tips—checking for refrigerant leaks the right way. In this guide, you’ll learn quick checks you can do today, how to safely confirm a leak, and when to bring in a licensed technician. We’ll also cover A2L (R-32) trends in the U.S., which make good leak practices even more important. Everything below follows a “simple first, expert next” approach so you can act fast, protect your equipment, and keep spaces comfortable. If you want a deeper care routine, our step-by-step PTAC maintenance guide is a great companion.

The common concern: “Is my PTAC leaking refrigerant?”

Most people notice a leak only after the room won’t cool like it used to. Common complaints include longer run times, short cycling (on–off–on), or ice forming on the indoor coil. The issue matters because refrigerant is the “bloodstream” of your PTAC—if it escapes, heat transfer stalls. Running a unit while it’s undercharged can overheat the compressor, corrode coils, and stress electrical parts. That turns a small repair into a pricey replacement. It’s also a safety and compliance topic: many newer units use R-32 (A2L), a refrigerant with mild flammability, which demands smart handling and solid ventilation during any work. Good news: you don’t need advanced tools to spot the early clues. Start with eyes and ears, then do a quick soapy-water test on accessible fittings. When signs are strong or access is limited, call a licensed pro to test, repair, evacuate, and recharge the system correctly.

Quick visual and audio checks you can do now

Begin with the front panel off and power off. Look for:

• Oily residue on copper lines, coil ends, or joints (refrigerant carries a little oil that can mark a leak path).

• Ice buildup on the evaporator coil or suction line. Ice in warm weather usually means low charge or airflow issues.

• Water pooling where it doesn’t belong—backup from an imbalanced system can point to refrigerant loss.

Next, listen closely (power on, fan running):

• Hissing near flare nuts, Schrader cores, or service valves can mean gas escaping.

• Gurgling/bubbling can signal air intruding where only refrigerant should flow.

If these signs match what you’re hearing and seeing, skim our plain-English explainer on signs of a refrigerant leak for a refresher on symptoms
 

Want broader upkeep beyond leaks? See Maintaining Your PTAC Unit: Cleaning, Filter Changes & Efficiency Tips. 

The soapy-water test: fast DIY confirmation

This is a safe, low-tech way to spot active leaks on accessible parts (think flare joints, threaded fittings).
You’ll need: a spray bottle, mild dish soap, and clean water.

Steps (power off):

1. Mix 50/50 soap and water.

2. Spray lightly on suspect joints and caps.

3. Watch for steady bubbles that form and grow—that’s refrigerant pushing through.

4. Wipe clean, note the spot, and do not overtighten fittings unless you’re trained; over-torquing can worsen leaks.

5. Restore panels, label the area, and plan next steps.
   
   

Keep in mind: This method can’t reach hidden coils or micro-leaks. If your PTAC still struggles, a pro can use electronic detectors (down to parts per million), UV dyes, or pressure tests to find smaller issues. While you’re inspecting, also check your condensate drain—a clogged drain can mislead you by adding water where you expect refrigerant clues. Need replacement parts and sealants? See our stocked accessories and line sets.

• Accessories

• Line sets

Quarterly tasks that prevent leaks (stop problems early)

Prevention is cheaper than repair. A simple every-3-months routine protects coils and connections:

• Clean coils (indoor and outdoor) to reduce corrosion risk and keep pressures in range. Dust + moisture can create tiny pits that become leaks.

• Inspect connections: look at flare joints and braze areas for discoloration or oil traces.

• Clear the drain so water never sits near metal parts.

• Check the filter monthly; replace as needed to maintain airflow and avoid coil freeze-ups that stress tubing.

Build this into your property schedule for hotels and multi-family sites. For units near upgrades or replacements, review options like PTAC heat pumps or R-32 PTAC units to improve efficiency and serviceability. If you’re planning new installs, our PTAC sizing chart & guide helps you choose the right capacity and voltage for U.S. applications and building codes.

Annual checks only licensed pros should handle

Some tasks require training, tools, and EPA Section 608 certification:

• Refrigerant level verification using gauges or digital manifolds to confirm superheat/subcooling.

• Electronic leak detection (heated diode, infrared, ultrasonic) and UV dye tracing for slow, hidden leaks.

• Nitrogen pressure testing and vacuum/evacuation to manufacturer specs before recharging.

• System electrical review (contactors, capacitors, wiring) when leaks occur near energized parts.

• Documentation for warranty and environmental compliance.

For lineset work on DIY-style connectors, see our walk-through on safe pressure testing and leak checks for quick-connect systems if that matches your setup
When a replacement makes more sense, compare through-the-wall air conditioners or hotel heat & air units for your property’s use case.

Safety first: gear, ventilation, and emergency steps

Refrigerant can displace oxygen in a closed room and can super-cool skin/eyes on contact. Keep safety simple and strict:

• Wear gloves and safety goggles any time you’re near the sealed system.

• Work with good ventilation; avoid low, enclosed spaces.

• If you suspect a big release, evacuate the area and ventilate before re-entry.

• Power down the unit before removing panels or touching wiring.

• Treat frostbite-like exposure by flushing with lukewarm water and seeking medical care.

With R-32 (A2L) becoming common in U.S. equipment, respect mild flammability: avoid sparks, don’t smoke, and follow local code and manufacturer instructions. For a plain-language refresher on R-32 safety basics, see our guide and share it with your maintenance team.
More hands-on care tips are posted frequently on our HVAC Tips 

Clear triggers to call a licensed technician (don’t wait)

Stop DIY and pick up the phone when you notice:

1. Room won’t cool even after filter changes and coil cleaning.

2. Short cycling (rapid on/off) that continues after airflow fixes.

3. Strong hissing at joints or caps, or bubbles on multiple fittings.

4. Ice returns quickly after a full thaw and restart.

5. Bills spike with no utility rate change.

6. Leaks near live electrical parts or any burnt wire smell.

7. Units charged with R-32 where special A2L procedures apply.

A pro will isolate the circuit, verify pressures, perform electronic detection, repair the leak correctly (not just “top off”), pull a deep vacuum, weigh in the charge, and log the service. If age, coil condition, or repeated leaks suggest replacement, explore R-32 through-the-wall units or package units sized to your building.

Frequently asked questions 

How do I know if my PTAC is leaking refrigerant?
Weak cooling, longer run times, ice on coils, or hissing near fittings are common clues. A quick soapy-water test on accessible joints can confirm bubbles.

Is it safe to run a PTAC that’s low on refrigerant?
No. It can overheat the compressor and damage coils. Shut it down and schedule service.

Can I just add more refrigerant?
Adding charge without fixing the leak is a temporary patch and may violate rules. The system must be leak-repaired, evacuated, and recharged by a pro.

What’s different about R-32 (A2L)?
It’s low-toxicity and mildly flammable. Follow manufacturer guidance and local code. Pros use A2L-rated tools and ventilation steps.

How often should I do maintenance?
Check filters monthly, do coil/connection/drain checks quarterly, and book a yearly pro inspection. For a full routine, see our PTAC maintenance guide.