Refrigerant leak detection in Pakenham — sniffer + UV dye process.

When a Pakenham split system stops cooling like it used to — or a ducted reverse-cycle in a Cardinia Lakes home starts struggling on hot days — the first diagnostic is the refrigerant gauges. If the high-side and low-side pressures, superheat and subcooling all point to an undercharge, we have a leak. From there it’s a two-stage hunt.

Stage one — electronic sniffer scan.

The first stage is a calibrated electronic refrigerant sniffer (heated-diode sensor) walked slowly around every accessible joint on the system. On a typical Cardinia residential install that’s about 14 inspection points: indoor flare A, indoor flare B, line set entry through the wall, line set exit at the outdoor unit, outdoor flare A, outdoor flare B, both service valve caps, both service valve schrader cores, the brazed joints on the manifold, and the indoor and outdoor coil headers. The sniffer detects R32 or R410A down to about 3 grams per year — small enough to catch a leak that’s been bleeding out over 18 months. Stage one finds about 75% of leaks on the first visit.

Stage two — UV dye and return visit.

The 25% of leaks the sniffer misses on day one are usually intermittent (vibration cracks that open and close depending on pressure cycling) or hidden inside the wall or roof cavity. For those, stage two is UV fluorescent dye injection. We charge a measured amount of leak tracer dye into the system, run it for 7–14 days, then come back with a UV inspection lamp and look for the bright green stain at the leak point. The dye also makes the inside-the-wall leaks findable — the stain travels along the copper and shows up at the next accessible joint downstream. Stage two catches about 22% more leaks, taking the cumulative find rate to ~97% by the end of the second visit.

Why we don’t just top up and walk away.

A lot of Pakenham customers ring us after a previous installer quoted “$300 for a re-gas” with no leak detection. That quote is dishonest and illegal. Under the Ozone Protection and Synthetic Greenhouse Gas Management Regulations, ARC RHL-licensed technicians must make a reasonable effort to locate and repair a leak before recharging. Topping up without finding the leak means the customer pays $300 in 2026, $300 in 2027, $300 in 2028, and the refrigerant ends up in the atmosphere — R32 has a Global Warming Potential of 675 (R410A is even worse at 2,088). The EPA can audit our refrigerant purchases against the jobs we’ve logged; an installer who’s topping up without leak-finding gets flagged on the audit and risks their RHL.

The honest call is: find the leak, repair it, evacuate the system, recharge to manufacturer spec, document everything, and you don’t ring us for the same job next year. That’s the only way the numbers work out cheaper for you in the long run.

Where the leak usually is.

After hundreds of Pakenham leak jobs, the failure pattern is clear:

• Outdoor flares (~55%): bad installation, no re-flare, or vibration cracks. The most common single cause across Cardinia Lakes and Officer.
• Indoor flares (~20%): same root causes, harder to reach because they’re behind the head unit.
• Service valve schrader cores (~10%): rubber seal degrades after repeated gauge attachments.
• Brazed line-set joints (~8%): inside walls or roof cavity, usually only found by UV dye.
• Condenser coil pinholes (~5%): aluminium fin corrosion, more common on rural-edge Cardinia properties next to crop fertiliser drift.
• Indoor evaporator (under 2%): rare on residential, usually a manufacturing defect under warranty.

The honest repair-and-recharge quote.

Once we find the leak, the repair scope depends on what failed. A flare re-cut and re-flare is typically $60–$120 of labour. A brazed joint repair is $180–$320. A schrader core replacement is $40–$80. Then we evacuate to under 500 microns (15–30 minutes), recharge with R32 by weight (not by pressure — that’s the rookie way), and commission. Recharge on a typical 5 kW split is ~1.0 kg of R32 at about $180–$240 worth of gas. Total end-to-end jobs at this site usually land between $480 and $780 for the repair + full recharge, with the stage-one leak-detection fee credited against it.

2026 leak detection pricing — Pakenham.

Stage one electronic sniffer (single split): $190–$240. Stage one (ducted RC): $280–$360. Stage two UV dye add-on: $160–$220. Full diagnose-repair-recharge (typical): $480–$780. If we find the leak in stage one and repair on the same visit, the detection fee is credited off the repair invoice. EPA-compliant refrigerant recovery is included on every job — we never vent.