HVAC leak detection with one detector. Refrigerant in the system or not.
For HVAC leak detection, the DXR-240 Hydrogen & Refrigerant Leak Detector sniffs HFC, HFO and HC refrigerants on a charged system. It also finds 5% hydrogen / 95% nitrogen tracer gas on a recovered one. As a result, you can prove the repair is tight before a single ounce of refrigerant goes back in.
HVAC leak detection for charged and empty systems.
Roll up to any job ready for whatever is in the lines. Most technicians carry a refrigerant sniffer for charged systems but have nothing for an empty one. The DXR-240 carries a refrigerant sensor and a selective hydrogen sensor, so the same detector covers both situations.
System still charged
Sniff directly for the refrigerant that’s already there — no recovery, no downtime to start the search.
- HFC, HFO and HC refrigerants — R-410A, R-32, R-404A, R-134a, R-1234yf, R-290, R-600 and more
- Sensitivity to ~1 g/yr on HFC, HFO and hydrocarbons
- Quick screening on service calls and PM visits
System recovered or empty
Charge the circuit with non-flammable 5% H₂ / 95% N₂ tracer gas and locate the leak with the same DXR-240.
- 1×10⁻⁵ cc/s sensitivity on H₂/N₂ (≈1 g/yr refrigerant equivalent)
- Test coils, line sets and new installs with zero refrigerant in play
- Tracer gas can be safely vented when testing is complete
Prove the repair before the refrigerant goes back in.
With a refrigerant-only sniffer, the usual way to confirm a repair is to recharge and hope. If the braze still weeps, that refrigerant has to be recovered again — more labor, more loss, another truck roll. With hydrogen tracer gas, the coil or component is leak-checked and confirmed tight first. Refrigerant is only returned once you know the repair holds.
- 01RecoverReclaim the refrigerant charge per EPA practice.
- 02Charge 5/95Pressurize with H₂/N₂ tracer gas to a safe test pressure.
- 03PinpointSweep joints within ¼″ at about 1″ per second.
- 04RepairBraze, replace the fitting, or swap the coil.
- 05Verify with H₂Re-pressurize and re-sniff. Confirm zero leak.
- 06Vent, evacuate, rechargeRelease the tracer, pull vacuum, return refrigerant.
Why hydrogen tracer gas improves HVAC leak detection.
A smaller molecule finds a smaller hole, in the right place. Hydrogen is the smallest, lightest molecule there is. It escapes through openings that refrigerant, dye and bubbles can’t reveal. Then it rises and disperses quickly instead of hanging around the leak.
Refrigerant, however, is heavier than air and tends to pool into a plume. That plume can make a neighboring joint read as the leak. Repairing the wrong joint then means another expensive service call. Hydrogen’s low natural background in air keeps false readings low, so the highest reading is the leak.
| Method | Min. leak rate | ≈ Refrigerant loss |
|---|---|---|
| Soap bubbles | ~1×10⁻² cc/s | ~100 oz/yr |
| UV dye | Visual only | Not measurable |
| Standard refrigerant sniffer | ~1×10⁻⁴ cc/s | ~1 oz/yr |
| H2Leak H₂/N₂ tracer | 1×10⁻⁵ cc/s | ~0.10 oz/yr |
HVAC leak detectors: pick the one that fits your work.
HVAC and refrigeration leak detection, residential to industrial.
Residential & light commercial
Split systems, heat pumps, mini-splits and ductless units — including leaks inside walls and ceilings.
Commercial HVAC
Rooftop units, VRF/VRV systems and chillers with long piping runs and many joints.
Commercial refrigeration
Supermarket racks, display cases, walk-in coolers and freezers — evaporators, condensers, TXVs and brazed joints.
Commissioning & retrofits
Confirm new installs and replacement coils are tight before the first charge.
Leak repair rules now reach smaller systems.
Since January 1, 2026, the EPA’s Emissions Reduction and Reclamation rule has applied leak repair requirements to more systems. It covers appliances holding 15 lb or more of an HFC refrigerant (or substitute) with a GWP above 53. That is down from the 50 lb threshold of the older Section 608 rules. Owners must also calculate leak rates when adding refrigerant and repair leaks that exceed the thresholds.
Accurate HVAC leak detection helps contractors and their customers stay ahead of these requirements. Verifying each repair before recharging also supports programs such as EPA GreenChill.
Regulations change; confirm current requirements with the EPA for each system.
HVAC leak detection FAQs
Is 5/95 hydrogen/nitrogen tracer gas safe?
Yes. At 5% hydrogen, the blend is below hydrogen’s flammability limit and is non-toxic. It can also be released to atmosphere when testing is done. The detectors themselves are not explosion-proof and must not be used in hazardous atmospheres.
Do I need the DXR-240, or will a hydrogen-only detector do?
If you want to check charged systems without recovering first, choose the DXR-240. If you always recover and test with tracer gas, the DXH-240 or TLD.500 covers that work.
Does it work with A2L refrigerants like R-32?
The DXR-240 detects HFC and HFO refrigerants, including R-32, plus hydrocarbons R-290 and R-600. Hydrogen tracer testing works regardless of the refrigerant the system will run on.
Where do I get tracer gas?
5% H₂ / 95% N₂ (often called forming gas) is available from most industrial gas suppliers. Contact us and we’ll help you get set up.
Stop recharging to find out.
Get pricing on the DXR-240 or ask which HVAC leak detection tool fits your service work.