Does your split system need regassing? Almost certainly not — and here's how to tell.
“It's due for a regas” is one of the most common things Australians are told about their air conditioner, and for a healthy system it is simply not true. A split system is a sealed circuit: the refrigerant isn't consumed, it circulates forever. If yours is genuinely low, gas has escaped — and topping it up without finding the leak means paying for the same gas twice. Here's what real servicing involves, what it doesn't, and the one question that separates a good technician from an upsell.
Reviewed by the Mission Green Energy Team · Updated August 2026
Does a split system
actually need regassing?
The short answer, before the detail.
No. A healthy split system never needs regassing — not annually, not every five years, not ever. Your air conditioner is a sealed refrigerant circuit. The gas inside it isn't a consumable like petrol or printer ink; it circulates round and round, changing state between liquid and vapour, and it is never used up. Nothing about running the unit consumes refrigerant.
So if a technician tells you your system is low on gas, the correct next sentence is not "let's top it up". It is "where is it leaking?" Refrigerant that is missing went somewhere. It escaped. And a system that is topped up without the leak being found and repaired will simply lose the new gas the same way it lost the old — sometimes within a single season. You are renting cold air.
This matters because "annual regas" is one of the most common upsells in the industry, and it's sold as routine maintenance to people who have no way of knowing it isn't. Servicing is real and worth doing. Regassing a healthy system is not a service — it's a symptom being sold as a cure.
Why do so many people believe
it needs topping up?
Three honest reasons, only one of which is anyone acting in bad faith.
Cars really do need it
Car air conditioning genuinely does lose refrigerant over time — a vehicle’s system uses flexible hoses and rotating shaft seals that flex, heat-cycle and vibrate down a road for years. Home split systems are rigid copper, brazed, and bolted to a wall that doesn’t go anywhere. People reasonably assume the two work the same way. They don’t.
The symptom looks like “low gas”
A unit that’s blowing weak, warm or icing up can be low on refrigerant — but far more often it’s a filthy filter, a blocked outdoor coil, a failing fan or a control fault. All of those present as “not cooling properly”. Gas is the easiest thing to blame and the fastest thing to bill.
It’s a profitable default
A regas is a quick, high-margin job that produces an immediate improvement the customer can feel — right up until the gas leaks out again. Proper leak detection takes time and skill and sometimes ends in an awkward conversation about replacing the unit. Not every operator chooses the harder path.
So what does a split system
genuinely need?
Real maintenance is mostly airflow and cleanliness — and most of it you can do yourself, for free.
Almost every “my aircon isn’t working properly” call comes down to airflow, not refrigerant. Here is what actually keeps a unit efficient, in rough order of how much difference it makes per dollar spent:
- Clean the indoor filters — every few weeks in heavy use. This is the single highest-value maintenance task and it is free. Pop the front cover, slide the mesh filters out, rinse under a tap, dry, put them back. Clogged filters choke airflow across the evaporator coil, which makes the unit work harder, run longer, cost more and — in cooling — can freeze the coil solid.
- Keep the outdoor unit clear. It needs to dump heat, so it needs air. Cut back the shrub that has grown across it, sweep away leaf litter, and don’t box it in behind a screen with no clearance. Hose the fins gently (never a pressure washer — the fins bend and then they insulate rather than transfer heat).
- Watch the condensate drain. The indoor unit produces water when cooling, and that water leaves through a small drain line. Blocked lines are the most common cause of a unit dripping inside — see our guide on split system problems and what causes them.
- Have it professionally serviced periodically — not annually by default. A genuine service includes a deep clean of the indoor coil and blower wheel (where mould and biofilm build up and cause smells), checking electrical connections and running currents, verifying drainage, and measuring operating pressures and temperatures to confirm the charge is correct — not to top it up. How often depends on your environment: a coastal or dusty site, a home with pets, or a unit running most of the year needs it more than a lightly used unit in a clean suburb.
Notice what isn’t on that list. Adding gas is not maintenance. It is a repair, and it should only ever follow a diagnosis.
What if the system genuinely
has lost refrigerant?
Then you have a leak, and there is a correct order of operations. Insist on it.
Sometimes a system genuinely is undercharged — a poor installation that was never charged correctly, a flare joint that has vibrated loose, corrosion on the outdoor coil (common near the coast), or physical damage. That is a real fault and it deserves a real repair. The correct sequence is:
- Find the leak. Nitrogen pressure testing, an electronic leak detector, or UV dye circulated and then inspected. Not guesswork.
- Repair it, then pressure-test again to prove the repair held.
- Evacuate the system with a vacuum pump to remove air and moisture. Skipping this is how you get acid, sludge and a dead compressor a year later.
- Charge by weight to the figure on the manufacturer’s nameplate. Not "until it feels about right".
If a repair is quoted and the unit is old, do the arithmetic honestly. A leak repair plus evacuation and a full charge on an ageing split system can approach a meaningful share of a new, far more efficient unit — and the new unit comes with a warranty and a much better running cost. There is no shame in replacing rather than repairing; there is real cost in repairing something twice.
So — what should you
actually do?
Ordered by the situation you’re in.
If someone has offered you a routine annual regas, decline it and ask what fault they diagnosed. If there isn’t one, you don’t need gas. If your unit isn’t cooling or heating well, clean the filters and clear the outdoor unit first, then run it again for a day — a genuinely large share of complaints end there, at no cost. If it’s still poor after that, book a diagnostic service and insist the technician explains what they measured before anything is added or replaced. If they find a leak, get the repair quoted properly and weigh it against the age and efficiency of the unit. And if the unit is 12–15 years old and failing, replacement is usually the better economic call — a modern inverter unit is dramatically cheaper to run than the fixed-speed units of a decade ago.
Mission Green doesn’t service air conditioners, so we have nothing to sell you here either way. That’s rather the point of putting it in writing.
Does a split system air conditioner need regassing?:
your questions, answered.
No — not as routine maintenance. A home split system is a sealed refrigerant circuit. The refrigerant is not consumed by running the unit; it circulates indefinitely, changing between liquid and vapour. A healthy system will hold its original charge for its entire working life. If a system is genuinely low on refrigerant, it has a leak, and the correct response is to find and repair the leak — not to top it up. Adding gas to a leaking system without repairing it simply means the new gas escapes the same way the old gas did, often within months. Any offer of a scheduled or annual regas on a system with no diagnosed fault should be declined.
There is no single correct interval, and be sceptical of anyone who insists there is. Clean the indoor filters yourself every few weeks during heavy use — that is the highest-value maintenance there is and it costs nothing. Keep the outdoor unit clear of leaves and vegetation. Beyond that, a professional service every year or two is reasonable for a hard-working unit, a coastal or dusty location, or a home with pets, while a lightly used unit in a clean environment can go longer. What matters is what the service actually includes: a deep clean of the indoor coil and blower wheel, checking the condensate drain, inspecting electrical connections and running currents, and measuring operating pressures and temperatures to confirm the charge is correct. A service that consists mainly of adding refrigerant is not a service.
Prices vary widely by location, unit type and what is actually included, so treat any single figure as indicative and get a written scope before booking. The more useful question is what you are paying for. A basic filter clean is something you can do yourself in ten minutes for nothing. A genuine professional service should include a deep chemical clean of the indoor coil and blower wheel, drain clearing, electrical checks and performance measurement — and should be quoted as such. A quote that leads with “regas included” is a warning sign, not a feature, because a healthy system does not need gas. Always ask what the service covers item by item, and ask what happens if a fault is found: whether diagnosis is included, and whether you will be quoted before any repair work starts.
Because refrigerant is rarely the problem. The most common causes of poor cooling are airflow related: clogged indoor filters, a dirty evaporator coil, or an outdoor unit that cannot dump heat because it is choked with leaf litter or boxed in by vegetation. Beyond that, a failing indoor or outdoor fan, a faulty control board or sensor, a unit that is simply undersized for the room, or doors and windows left open will all present as weak cooling. Start with the free checks: clean the filters, clear the outdoor unit, and make sure nothing is obstructing airflow at either end. If performance does not improve after that, book a diagnostic service and ask the technician what they measured before anything is added or replaced. Low refrigerant is a possible diagnosis, but it should be the conclusion of an investigation, not the opening offer.
No. Handling refrigerant in Australia requires a refrigerant handling licence issued under the Australian Refrigeration Council — the ARCtick scheme — and the business doing the work needs a refrigerant trading authorisation to buy and hold refrigerant. There is no legitimate DIY path, and the top-up cans sold for car air conditioning are not suitable for a home split system. Beyond the licensing question there is an environmental one: releasing refrigerant to atmosphere is an offence, and these gases have a global warming potential hundreds to thousands of times that of carbon dioxide. There is also a practical reason not to try: charging a split system correctly means charging by weight to the manufacturer’s specification after evacuating the system, which needs scales, gauges and a vacuum pump. You can check whether a technician is licensed on the ARCtick website before booking.
Four steps, in this order. First, find the leak — by nitrogen pressure test, electronic leak detector or UV dye, not by guesswork. Second, repair the leak and pressure-test again to prove the repair held. Third, evacuate the system with a vacuum pump to remove air and moisture, because skipping this step introduces moisture that forms acid and can destroy the compressor later. Fourth, charge by weight to the figure on the manufacturer’s nameplate rather than by feel. If a technician proposes to skip straight to step four, the gas will leave again. It is also worth doing the economics honestly before authorising the work: on an ageing unit, a leak repair plus evacuation and a full charge can approach a meaningful share of the cost of a new, far more efficient system that comes with a fresh warranty.
Where these figures come from.
Figures on this page are drawn from primary sources and were current as at August 2026. Programs, prices and standards change — confirm at the source before relying on a number.
- Australian Refrigeration Council — ARCtick refrigerant handling licence register (arctick.org)
- DCCEEW — Refrigeration and air conditioning regulation in Australia (dcceew.gov.au)
- energy.gov.au — Heating and cooling guidance for Australian households
- Energy Rating — Air conditioner efficiency and running cost data (energyrating.gov.au)
- ACCC — Consumer guarantees on services, including repairs (accc.gov.au)