Heat pump refrigerant handling: the licence check most homeowners skip

I was on a job in Reservoir a few months back, standing next to a customer while her installer connected the outdoor unit's line set. She asked him, quite reasonably, "so you're licensed for this, yeah?" He said yes and kept working. She didn't ask what "this" actually covered, and neither did I press it, because it wasn't my install. But it stuck with me, because the answer she got wasn't really an answer. There are several licences that could apply to that moment, and only one of them covers what he was doing with his hands.

We've already covered how to vet a heat pump installer more broadly, including sizing method and general credentials, in How to Vet a Heat Pump Installer. This piece goes narrower. It's about the specific licence that governs anyone who breaks into a sealed refrigerant circuit, why that check gets skipped so often, and what happens when it's skipped and something goes wrong.

Why refrigerant handling is its own licensing category

A heat pump isn't just an electrical appliance. The refrigeration circuit, compressor, coils, and the line set connecting the indoor and outdoor units, is a sealed pressure system charged with a fluorinated gas. Opening that circuit, whether to braze a joint, evacuate air and moisture, or add refrigerant, is regulated separately from general electrical or plumbing work in both Australia and the US.

In Australia, anyone handling refrigerant needs an ARCtick licence issued under the Ozone Protection and Synthetic Greenhouse Gas Management Act. It's a federal scheme, administered through the Australian Refrigeration Council, and it's tiered: some licences cover only self-contained low-charge systems, others cover full split systems and commercial refrigeration. The electrical licence that lets someone wire up a heat pump is a completely different credential. You can hold one without the other, and plenty of general electricians do.

In the US the equivalent is EPA Section 608 certification under the Clean Air Act, again tiered by refrigerant type and system size, with Type II covering high-pressure appliances like most split system heat pumps. Some states layer an HVAC contractor's licence on top of that federal certification, so the checks aren't identical state to state, but the 608 card is the non-negotiable floor.

The specific credential to ask for, by name

Here's where I think most homeowners get it wrong. They ask "are you licensed" and accept a nod. Ask instead for the actual card or number: an ARCtick licence number in Australia, or an EPA 608 certification card in the US, and check it against the register. The Australian Refrigeration Council maintains a public licence lookup, and EPA-approved certifying organisations issue verifiable cards with a certification number you can call to confirm.

I'd argue this single check matters more than the sizing conversation for one reason: a badly sized heat pump runs inefficiently and annoys you for years, but a poorly evacuated refrigerant circuit or a leak from a rushed brazed joint can fail within a season, and it can also mean synthetic greenhouse gas venting straight into the atmosphere, which is exactly what the licensing scheme exists to prevent. It's not a paperwork formality. It's the difference between a system that holds its charge for fifteen years and one that's low on refrigerant by year three.

Red flags that show up before the unit's even installed

A few patterns are worth watching for during quoting, before any tools come out.

The installer can't quote a licence number without checking with someone else, or the number belongs to the business rather than the individual doing the physical work. In Australia, ARCtick licences are issued to individuals, not just companies, so the person brazing the line set should have their own number, not just "the business is licensed."

There's no mention of a vacuum pump or micron gauge anywhere in the process description. Evacuating the line set to remove moisture and non-condensable gases before charging is a basic step, and it takes time, usually 30 to 60 minutes minimum depending on line length. If a quote or a chatty pre-install conversation implies the whole line set connection and charge will be done in under an hour total, that's a shortcut, and it's the kind of shortcut that shows up as a mysterious loss of capacity eighteen months later.

Refrigerant type isn't mentioned anywhere in the paperwork. Most current residential heat pumps use R32 or R410A, and increasingly R290 (propane) in some newer models, each with different handling requirements and flammability classes. A properly licensed installer will know which refrigerant they're working with and won't blink if you ask.

There's pressure to "top up" an old system rather than properly diagnosing why it's low. A refrigerant circuit is sealed. If a heat pump needs regassing, something is leaking, and simply adding refrigerant without finding and fixing the leak is both bad practice and, depending on jurisdiction, arguably a breach of the licensing conditions around preventing emissions.

What proper installation practice actually looks like on site

When I've watched good installers work, and I mean the ones I'd actually recommend to a friend, the refrigerant-side steps follow a fairly predictable order. Line sets get pressure tested with nitrogen to check for leaks before anything is evacuated. Then the system is pulled down to a deep vacuum, checked against a micron gauge rather than just "run the pump for a while and hope," held to confirm it's not rising, and only then charged to the manufacturer's specified weight, usually verified against the compliance plate rather than eyeballed.

None of that is visible to a homeowner standing at a reasonable distance, and none of it takes long to describe if you ask. That's actually the test I'd suggest: ask the installer to walk you through those four steps in their own words before they start. A properly licensed, competent tech will answer in under thirty seconds without hesitating. Someone who's never done a proper vacuum test will either get vague or start talking about something else, usually the thermostat app.

Where this intersects with sizing and running costs

Refrigerant charge accuracy and correct system sizing aren't separate issues, they compound. An undercharged system on a correctly sized heat pump will underperform in exactly the way an oversized unit does: short cycling, poor dehumidification, higher bills than the spec sheet promised. We've written before about how oversizing quietly ruins comfort and running costs, but an undercharged, correctly sized unit produces almost the same symptoms from a completely different cause. If you're chasing the running-cost numbers we discuss in Heat Pump vs Gas Heating running costs, a bad refrigerant job will quietly wreck them regardless of how well the unit was sized on paper.

This is also where cold-climate performance claims get undermined. A unit rated for genuine cold-climate operation, the kind of spec sheet claims we unpack in What 'Cold-Climate Rated' Actually Guarantees, depends on the refrigerant circuit being charged exactly to spec. Low charge shows up hardest at the temperature extremes the unit was supposedly built to handle, which is precisely when you need it working properly.

Warranty paperwork and the licence number connection

Manufacturer warranties on heat pumps, whether it's a ducted system or something like the hot water heat pump units we cover for domestic hot water, almost universally require installation by a licensed, qualified technician, and increasingly ask for the licence number to be recorded on the commissioning paperwork. If your installer can't produce that number for the warranty registration, you may find yourself with a technically "installed" system that isn't actually covered if the compressor fails in year four. I've seen homeowners discover this the hard way, mid-claim, which is a genuinely bad time to find out.

Ask for the licence number to be written on your invoice and the warranty registration form, not just mentioned verbally. It costs the installer nothing to write it down, and it gives you something to check later if you ever need to make a claim.

A quick note on ducted systems and multiple contractors

Ducted heat pump installs, the kind covered in our ducted vs split system comparison, often involve more than one trade: an electrician for the circuit, a refrigeration-licensed tech for the line set and charge, sometimes a separate ductwork installer. On these bigger jobs it's worth asking explicitly who on the crew holds the refrigerant handling licence, because it's easy to assume the lead contractor personally does all the work when in practice an apprentice or subcontractor might be the one actually opening the circuit. Ask by name. It's a fair question and any legitimate outfit will answer it without getting defensive.

Whilst I know most homeowners just want the unit working and the quote reasonable, this is the one check that takes about two minutes and genuinely protects both your warranty and, less selfishly, the atmosphere. Worth the awkward question.