R-32 Refrigerant Leak Detection: Tools and Tips for Homeowners and Techs

Alright Folks—Tony Here 

You’ve installed your shiny new R-32 3–5 ton AC and gas furnace system, fired it up, and... wait a second—cooling ain’t what it should be. Lines feel warm, the coil’s sweating, and that air coming out the vent just ain't cold.

You might have a leak on your hands. And let me tell you—R-32 isn’t like the old R-22 days where you’d just soap up a joint and hope for bubbles. This stuff’s classified A2L, meaning it’s mildly flammable, requires special handling, and deserves a little more respect.

Let’s break down:

• How to detect R-32 refrigerant leaks

• What tools you need

• Where leaks hide

• And how not to blow yourself up 😬

 

First: Why Leak Detection on R-32 Systems Matters More Than Ever

With R-32 being mildly flammable, you need to be more careful than with your old R-410A or R-22 systems.

That’s why the EPA and manufacturers like Goodman stress following A2L-specific protocols. You don’t want refrigerant pooling in enclosed spaces or near ignition sources. Want the official word? Here’s the EPA’s page on refrigerant classifications.

And let’s not forget—R-32 operates under higher pressure than R-22, and even more so than CO2 or propane systems. That means a leak not only causes poor performance—it can wreck your compressor and dump flammable gas into tight spaces.

 

What You’ll Need to Do the Job Right 🔧🧪

Leak detection is all about the tools. And no, your buddy’s ancient bubble bottle from the '80s isn’t gonna cut it. Here’s Tony’s go-to kit:

1. A2L-Rated Electronic Leak Detector

You need a detector that’s:

• UL certified for A2L refrigerants

• Sensitive down to 5 ppm

• Designed to avoid false positives from oil vapor or moisture

I like the Fieldpiece DR82 or Inficon D-Tek 3—both solid options. Check out this leak detector roundup by Inficon to compare features.

2. Nitrogen Test Kit + Regulator

R-32 is often blended with POE oil that masks leaks. So if you suspect one, you’ll want to:

• Recover the refrigerant

• Charge the system with dry nitrogen up to 300 psig

• Use a leak detection soap or listen with an ultrasonic sniffer

Note: Never use oxygen—that’s a recipe for explosion 💥

3. Bubble Soap (A2L Rated)

Don’t grab dish soap. Use proper micro-leak detection fluid. RectorSeal makes a version that clings better and detects leaks too small for bubbles.

 

Where Leaks Like to Hide (Tony’s Leak List) 🔍

After 25+ years in the field, I can tell you where these little suckers tend to pop up—especially in the 3–5 ton Goodman systems sold over at The Furnace Outlet:

1. Flare Fittings & Brazed Joints

• Vibration and pressure shifts loosen things up

• Always torque flares to spec

• Double-check post-braze cool-down with nitrogen test

2. Service Valves & Schrader Cores

• Schrader cores fail more than you’d think

• Always cap service valves with gasketed brass caps

3. Evaporator Coil U-Bends

• The U-bends and return bends at the coil ends are notorious for hairline leaks

4. TXV & Distributor Tubes

• Over-tightening the TXV or vibration fatigue can crack the connections

If you’re not sure, hit ‘em all with your detector. This EPA leak detection manual offers a great layout for where and how to scan each part of the system.

 

So You Found a Leak—Now What? 🤨

Here’s what NOT to do:

• Don’t just top off the refrigerant and walk away

• Don’t use sealants unless you're desperate

• Don’t pretend it’ll “settle in”

Instead:

• Recover the charge completely

• Pull a deep vacuum

• Repair the leak properly—braze, flare, or replace

• Pressure test with nitrogen

• Then recharge by weight per the nameplate

Still nervous? Courtesy Heating & Cooling put out a great guide on proper leak repair steps that mirrors what I preach.

 

R-32 and Safety: Let’s Talk Ventilation 😷💨

Remember: R-32 is heavier than air, and it’ll sink in low spaces. If you’re working in a basement, attic, or crawlspace—crack open some ventilation.

For garages and mechanical closets:

• Avoid open flame tools

• Keep ignition sources sealed or removed

• Use a fan if the space feels “stale”

Want to be extra safe? ASHRAE's A2L safety fact sheet gives clear guidance on room concentration limits and ventilation requirements.

 

Tony’s Tips for Leak-Free Installs 👨🔧✅

If you’re setting up a new R-32 system:

• Always pressure test with nitrogen before pulling a vacuum

• Don’t skip leak detection soap—even if you used a sniffer

• Let the system sit pressurized overnight if possible

• Make sure all caps are tight and torque-checked

• Replace every Schrader core with a new one (cheap insurance)

 

Final Words from Tony 🗣️

Look—R-32 isn’t rocket science. But it is different. You can’t treat it like your grandpa’s R-22 unit and expect the same results.

With higher pressure, lower GWP, and that A2L rating, leak detection becomes a serious part of your install or service call—not an afterthought.

If you’re dealing with a stubborn system, or you’re setting up a new Goodman bundle like the ones at The Furnace Outlet, take the time to leak-check it the right way.

Because nothing ruins a summer like a fried compressor, a hot house, and a customer on your voicemail asking, “Hey, why’s it blowing warm again?”

Worried about your 3.5 ton gas furnace installation? Visit my guide: What Every DIYer Should Watch For (Especially on 3.5 Ton Systems).

Stay sharp, stay safe—and don’t let that R-32 sneak away on you.

—Tony the Trusted Tech