Leak Detection and Repair for R‑32 Heat Pumps: Tony’s Pro Strategies

👋 Hello from Tony

Hey there, Tony here — back in your corner with some straight-up advice about one of the most common and often overlooked challenges on the job: leak detection and repair on R‑32 heat pumps. Look, I don’t care how perfect your install was or how much experience you have under your belt — sooner or later, you’re going to run into a refrigerant leak. That’s the nature of the game.

And with R‑32 becoming the refrigerant of choice these days — especially for those 2–5 ton residential and light commercial heat pumps — leaks can mean serious trouble if you’re not equipped to detect them quickly and repair them properly. R‑32 may have a lower global warming potential than R‑410A, and it’s more efficient too. But let’s not forget: it’s an A2L refrigerant — mildly flammable — so you have to up your game with safety as well as accuracy.

That’s why I put this guide together. I want to give you the kind of real-world, nuts-and-bolts advice that’s saved my bacon more times than I can count. You’ll learn my favorite leak detection tools, how to do it right the first time, and — most importantly — how to repair leaks in a way that’ll last, so you’re not hearing back from the homeowner next week with the same issue.

By the end of this article, you’ll have all the know-how to tackle R‑32 leaks like a pro. Ready? Let’s jump in.

 

🧭 Why Leak Detection is Critical with R‑32

With R‑32’s mildly flammable nature and increasing use in heat pumps, detecting and repairing leaks isn’t just about efficiency — it’s about safety and environmental responsibility. Even small leaks can:

• Hurt heat transfer, boosting power consumption and wear on the compressor.

• Affect subcooling and superheat, leading to improper system pressures.

• Create a potential safety hazard in enclosed spaces.

And don’t forget the legal implications. Under EPA regulations, you’re required to repair substantial leaks promptly — see the full refrigerant leak repair guidelines on the EPA’s official Section 608 page — or face steep fines.

 

🔍 Tools for Leak Detection

Before you go hunting, you need the right tools:

✅ Electronic Leak Detector: The most common, sensitive enough for R‑32. Look for an A2L-rated model so you’re in compliance.
✅ Ultraviolet (UV) Dye & Lamp: Add dye to the refrigerant and use a UV light to trace any leaks — works especially well in dark, tight spots.
✅ Bubble Solution: Old-fashioned soapy water is still a reliable quick-check.
✅ Ultrasonic Leak Detectors: Listen for the high-pitch hissing sound of gas escaping.
✅ Pressure Gauge & Micron Gauge: To confirm system pressure holds steady after repair.

And remember — never use an open flame as a “leak detector.” That might have flown back in the R‑22 days, but with R‑32’s flammability? Absolutely not.

You can see a full breakdown of leak detection tools on HVAC.com’s refrigerant leak detection guide — well worth a look.

 

🕵️♂️ Step-by-Step Leak Detection

Here’s my proven process — follow this order and you’ll catch most leaks fast:

1. Visual Inspection: Always begin with your eyes. Check coil joints, flare connections, and service valve caps. Look for oil stains or corrosion — classic signs of a slow refrigerant leak.

2. Pressurize the System: Pull the refrigerant, pressurize with dry nitrogen up to the system’s test pressure (usually around 150–250 psi for R‑32). Never exceed manufacturer guidelines.

3. Spray Bubble Solution: Go over every braze joint, flare, and valve with a bubble solution. Big leaks will foam up immediately — small leaks will produce tiny clusters of bubbles.

4. Electronic Leak Detector Scan: Run the detector along the refrigerant lines and around the coil, especially where you can’t reach easily with your hands.

5. Confirm with UV Dye (Optional): If you still can’t find it, add UV dye to the system, let it run for a cycle, and come back with your UV light to trace any glowing spots.

Here’s a very handy leak detection checklist you can refer to at any time on the ACCA’s refrigerant guidelines.

 

🔧 Repair Techniques for R‑32 Leaks

Once you find the leak, the next step is fixing it for good. Here’s how I do it:

✅ Recover the refrigerant: Pull all R‑32 out with a recovery machine — remember, always use an A2L-rated recovery unit.

✅ Prepare the area: Clean the area around the leak thoroughly. Sandpaper or emery cloth to expose clean copper. Oil and debris cause poor braze bonds.

✅ Brazing and Soldering:
Use high-silver brazing rods and oxyacetylene torch for the repair — never soft solder. Make sure to purge nitrogen through the pipe while brazing to prevent scale inside the tubing. This is extra important with R‑32 systems due to its sensitivity to contaminants.
If the issue is on a flare connection, cut it back and reflare properly with a calibrated flaring tool — and don’t over-torque the nut when you reconnect.

✅ Verify Repair: Pressure test the system up to design pressure with dry nitrogen, and pull a deep vacuum afterwards to make sure your repair holds. Don’t proceed with charging until you hold a vacuum for 15–30 minutes.

 

🧪 Charging and Final Checks

Once the leak is fixed and verified, you can move on to evacuating the system to at least 500 microns and recharging by weight. Confirm superheat and subcooling per the manufacturer specs before you wrap up.

And remember — repair isn’t just the braze joint. Check the whole system one more time for other potential leak spots. Pay extra attention to capillary tubes, Schrader valves, and flare connections.

 

🧯 Safety & Compliance Recap

When you’re handling R‑32 leaks, safety cannot take a back seat. R‑32 is mildly flammable — so you must:

✅ Ventilate the area before working.
✅ Have a proper fire extinguisher handy.
✅ Wear safety goggles and gloves.
✅ Check for stray sparks or ignition sources.
✅ Maintain your EPA Section 608 certification — the full rule set is on the EPA’s 608 page — so you stay legal and safe.

 

✏️ Wrap Up from Tony

And that, my friends, is what leak detection and repair looks like in the real world for R‑32 heat pumps — straight from my toolkit to yours. Taking the time to do it right — pressurizing properly, listening for leaks, brazing with nitrogen, pulling a deep vacuum — pays you back every time. Nothing feels better than knowing you left a system tight, tuned, and safe.

And hey — I’d never leave you without pointing you toward some quality equipment. When you’re looking for new R‑32 heat pumps or need specs on systems that are built to last, swing by The Furnace Outlet’s R-32 heat pump systems page. That’s where I send my customers who want proven performance.

Need some maintenance tips for your R-32 heat pump system? Visit this guide: Total Care Guide for R-32 Heat Pumps: Tony’s Pro Maintenance Routines.

Keep those leak detectors calibrated, wear the right PPE, and remember — attention to detail and patience are your biggest assets. Do that, and you’ll keep your customers comfortable, compliant, and happy for years to come.

Tony out — stay safe and keep it cool! 🧡