How to Use a Mastercool Recovery Machine: Step-by-Step Guide
Knowing how to run a recovery machine correctly is one of those foundational skills that separates a professional fridgie from someone who's just getting by. The process isn't complicated, but the sequence matters and the safety checks are non-negotiable.
This guide walks through the full recovery workflow using a Mastercool recovery machine: from pre-job checks through to system isolation after the cycle is complete. It's written for ARCtick-licensed technicians who want a clear, practical reference, and for apprentices learning the right habits from the start.
If you haven't yet selected a machine, the Mastercool recovery machines complete guide covers model selection and capacity matching before you get to the how-to stage.
Written by Rica Francia Macaspac, HVAC Shop content writer, in consultation with Aussie HVAC tradies and industry experts. Published: June 2025 · Last reviewed: June 2025.
Step 1: Pre-Recovery System Checks
Every recovery job starts with checks, not with connecting hoses. Skipping the pre-recovery phase is how technicians end up mid-cycle with a problem they could have caught at the start.
The goal of pre-recovery checks is to confirm the system is in a state that makes safe recovery possible, and to make sure your equipment is ready before any refrigerant starts moving.
Pressure Testing Completion
Before recovery begins, confirm that any required pressure testing or leak checking on the system has already been completed. Recovery is typically performed prior to repair work, but it can also follow a pressure test on a system being decommissioned.
The key point is that you need to know what's in the system and at what pressure before you begin. A system with an unknown pressure state or a suspected large leak is a different job to a standard recovery on a working system.
Use your thermometer or temperature probe to take note of ambient and system temperatures. Temperature affects recovery speed and the pressure readings you'll see during the cycle. A reliable thermometer from your kit makes this quick work. See HVAC Shop's thermometer and temperature measurement range if you need to kit out or replace worn instruments.
Isolation Valve Position Verification
Confirm that the system's service valves are in their correct starting positions for recovery. On split systems, this typically means both the liquid and suction line service valves are open to allow refrigerant to flow from the indoor and outdoor sections.
On larger commercial systems with multiple circuits or zone isolation, map out which sections you're recovering from and verify each valve accordingly. A mispositioned valve at this stage means incomplete recovery, which costs time and creates a compliance problem.
Safety Equipment Readiness
Confirm you have appropriate PPE for the refrigerant type you're working with. For R32 and other A2L refrigerants, this means working in a well-ventilated area and being aware of the flammability classification. Review Safe Work Australia guidance if you're working in a confined or poorly ventilated plant room.
Check that your recovery cylinder is correctly rated for the refrigerant type, within its certification period, and has sufficient remaining capacity for the job. An under-capacity cylinder mid-cycle creates a real problem. This is a quick check that takes seconds but matters significantly on larger commercial jobs.
Tradie Pro Tip: On large commercial jobs, weigh your recovery cylinder before you start. Knowing the tare weight and the cylinder's maximum fill weight tells you upfront whether you'll need to swap cylinders mid-job. Discovering you've run out of cylinder capacity halfway through a 20 kg recovery is an avoidable headache.
Recovery Machine Pre-Check
Give the Mastercool machine itself a quick visual inspection before connecting anything. Check hose condition for cracking or wear, particularly at the fittings. Verify oil level on the sight glass if your model has one. Confirm the machine's inlet filter looks clear, especially if your last job involved a contaminated system.
Check the auto-shutoff pressure settings are configured for the refrigerant type you're about to recover. R32 operates at different pressures to R410A or R22, so a pressure limit set for one refrigerant may cut out prematurely or allow too high a pressure on another. Consult your model's manual for the correct settings per refrigerant type.
Step 2: Connecting to the System
Connection sequence is one of the areas where mistakes happen most often, particularly for apprentices and technicians new to a specific machine. The sequence is logical once you understand the reason behind each step.
Hose and Coupler Setup
Use hoses and couplers that are rated for the refrigerant type and system pressures you're working with. For R32 systems in particular, confirm your couplers are compatible with A2L refrigerants. Mastercool's high-side and low-side coupler set is a practical pairing for recovery work across common refrigerant types.
Check that all hose fittings are clean and the valve cores are seated correctly at the service ports before connecting. Debris or a cross-threaded fitting at this stage causes refrigerant loss on connection, which is both a compliance issue and a waste of refrigerant you're trying to capture.
High-Side Connection Procedure
Connect the high-side hose to the system's high-pressure service port first. Before making the connection, verify the system is not running. On a system that has been off for some time, the high and low side pressures should have equalised. If you're seeing significantly elevated high-side pressure, investigate before connecting.
Make the connection with the service valve still closed, then open it slowly once the fitting is secure. A controlled connection avoids a sudden pressure surge that could damage hoses or fittings and minimises refrigerant release at the connection point.
Low-Side Connection Sequence
Connect the low-side hose to the suction service port using the same controlled approach. Secure the fitting fully before opening the valve. At this point, both hoses are connected to the system and you should see system pressure on both your high-side and low-side gauge readings.
Verify the readings look consistent with what you'd expect for a static system at the ambient temperature. A reading that's significantly off from saturation pressure for the refrigerant type at the current temperature is worth investigating before you start the cycle.
Liquid Recovery vs Vapour Recovery: Choosing the Right Mode
Before starting the machine, decide whether you're running liquid recovery or vapour recovery. This decision affects both connection setup and the speed of the job.
Vapour recovery draws refrigerant in gaseous form from the low-side port. It works on any system and is the simpler setup. On small residential systems with modest refrigerant charges, it's perfectly adequate and the default method for most residential work.
Liquid recovery draws refrigerant in liquid form from the high-side liquid line, which is significantly faster on larger systems. On a commercial job with 15 to 20 kg of refrigerant, liquid recovery can cut the cycle time considerably compared to vapour-only. However, it requires that your machine supports liquid recovery mode and that the system configuration allows it safely.
For R32 systems, liquid recovery is often the preferred approach on larger charges precisely because it reduces the amount of time that flammable refrigerant vapour is being moved through equipment in an enclosed space. Always confirm your machine and hose set are rated for the mode you choose.
Tech Specs Note: Mastercool recovery machines support liquid and vapour recovery modes, but the specific connection setup varies by model. Confirm the inlet and outlet port assignments for your model before starting. Running liquid refrigerant into a vapour inlet port can damage the machine. Check your model's manual if you're using a machine for the first time.
Step 3: Running the Recovery Cycle
With the system connected and your setup verified, you're ready to start the machine and begin the recovery cycle. This is the active phase of the job, and while the machine does most of the work, your role is to monitor progress and respond to anything that indicates a problem.
Starting the Machine
Start the Mastercool recovery machine according to your model's startup procedure. In most cases, this means ensuring the machine's outlet valve is connected to the recovery cylinder before starting, then powering the machine on. Do not start the machine with the outlet valve closed, as this can cause unsafe pressure buildup.
Once running, open the inlet valve to begin drawing refrigerant from the system. On a vapour recovery setup, this will be the low-side isolation valve. On a liquid recovery setup, open the liquid line connection. Open the valve gradually rather than fully at once to avoid a sudden flow surge.
Monitoring Pressure During Recovery
As the machine runs, watch the system pressure readings on your manifold gauges. You should see pressure dropping steadily as refrigerant is transferred to the recovery cylinder. The rate of pressure drop gives you a sense of how the recovery is progressing.
A sudden stop in pressure drop, or a pressure that stabilises well above what you'd expect at the ambient temperature, usually indicates one of a few things: a valve that isn't fully open, a hose restriction, or a cylinder that's getting close to full capacity. Each of these has a different response, so monitoring carefully helps you diagnose quickly.
On jobs in hot environments like Darwin warehouses or northern Queensland plant rooms, higher ambient temperatures mean higher system pressures throughout the recovery cycle. This is normal, but it does affect how the readings look compared to a Melbourne winter job on the same refrigerant type.
Tank Filling and Auto-Shutoff
Mastercool recovery machines include auto-shutoff features that stop the machine when the recovery cylinder reaches a set pressure threshold. This is a safety and compliance feature, not just a convenience. Recovery cylinders have a maximum fill level, and the auto-shutoff helps prevent overfilling.
Do not override or disable the auto-shutoff to try to recover more refrigerant into a near-full cylinder. If the machine cuts off before the system pressure has pulled down sufficiently, the correct response is to swap to a new recovery cylinder and continue, not to push the existing one past its limit.
Time Expectations for Different System Sizes
Recovery time varies considerably based on system size, refrigerant charge, machine capacity, and the recovery mode being used. A residential split system with a 1.5 to 2 kg charge on vapour recovery might complete in 10 to 20 minutes. A large commercial rooftop pack with 20 kg of refrigerant on a mid-capacity machine in vapour mode could take well over an hour.
Switching to liquid recovery on larger systems when the setup allows it can reduce that time significantly. If you're finding recovery times on commercial jobs are consistently longer than expected, reviewing machine capacity against job type is worth doing. The recovery units collection at HVAC Shop covers the full Mastercool range with capacity information to help match the right machine to the job.
Troubleshooting Slow Recovery
If recovery is running noticeably slower than expected and the cause isn't obvious from the pressure readings, work through the common causes systematically. Check that all valves in the circuit are fully open. Check the recovery cylinder isn't nearly full and creating high back-pressure. Check the machine's inlet filter condition if this is a contaminated system job.
On jobs in dusty environments like WA mine sites or regional NSW farm sheds, hose kinking or debris in fittings is a more common culprit than it would be on a clean commercial installation. A quick visual inspection of the hose run and connections usually resolves this quickly.
Step 4: Post-Recovery System Checks and Completion
Completing the recovery cycle is not the end of the job. The post-recovery phase confirms that recovery is genuinely complete, the system is properly isolated, and you have what you need for compliance documentation.
Verifying Recovery Completion
When the machine auto-shuts off or you've reached the target low pressure, close the inlet valve before stopping the machine. Then stop the machine and watch the system pressure for several minutes. A well-recovered system will hold at or near the auto-shutoff pressure without rising significantly.
If the pressure rises after shutting the machine off, residual liquid refrigerant in the system is flashing to vapour. This is common on larger systems or systems with long pipe runs, particularly on warm days when the refrigerant temperature is higher. The response is to restart the machine and continue recovery until the pressure stabilises at a level consistent with near-complete recovery.
In Australian conditions, pressure rise after initial shutdown is more common on summer jobs in Queensland and the Northern Territory, where ambient heat keeps residual refrigerant temperatures higher and flash-off more pronounced. Account for this when scheduling recovery time on hot-weather commercial jobs.
| Post-Recovery Check | What to Look For | Action if Issue Found |
|---|---|---|
| System pressure hold | Pressure stable at or near auto-shutoff threshold for 3 to 5 minutes after machine stops | If pressure rises, restart machine and continue recovery until stable |
| Recovery cylinder status | Cylinder pressure and weight within acceptable limits; not overfilled | Swap cylinder if near capacity before restarting; label with refrigerant type |
| Hose disconnection safety | Close service valves before disconnecting hoses; no refrigerant release at disconnection | If refrigerant releases on disconnection, check valve position and hose valve state |
| System isolation for repair | Service valves closed and capped; system confirmed isolated before repair work begins | Re-check valve positions if system pressure changes unexpectedly after isolation |
| Documentation | Refrigerant type, estimated quantity recovered, cylinder ID, date and technician ARCtick number recorded | Record immediately while on site; required for ARCtick compliance |
| Machine shutdown and storage | Machine valves closed; hoses disconnected and capped; machine stored clean and dry | Inspect and replace inlet filter if contaminated system was recovered |
Tank Status Verification and Labelling
Before disconnecting the recovery cylinder, confirm its pressure and approximate fill state. A recovery cylinder should be labelled with the refrigerant type recovered into it. Mixing refrigerant types in a single cylinder is a compliance issue and makes reclamation more complicated and costly.
If you've recovered from more than one system type during the day, keep separate cylinders for each refrigerant. R32 and R410A in particular should not be mixed. A labelling habit formed early in your career saves a lot of grief later.
Hose Disconnection Safely
Before disconnecting hoses from the system service ports, close the service valves first. This prevents any residual pressure from releasing at the fitting on disconnection. Once the valves are closed, disconnect the hoses and immediately cap or valve the service port to prevent contamination.
On couplers with self-sealing valves, the seal engages on disconnection, which reduces refrigerant release. This is one of the practical benefits of using quality couplers on recovery work. Check your coupler condition regularly, particularly the valve seals, as worn seals on frequently used couplers cause small refrigerant releases on every disconnection.
Documentation and Compliance
Under ARCtick requirements, refrigerant handling must be documented. Record the refrigerant type, estimated quantity recovered, the recovery cylinder identifier, the date of the job, and your ARCtick licence number. This documentation is your compliance proof if it's ever requested.
Some contractors complete this on paper job sheets and transcribe to digital records at the end of the day. Others use field service apps that record it in real time. Either approach works as long as the information is recorded before you leave the site. Getting into the habit of documenting on the day is much easier than trying to reconstruct records later.
The ARCtick compliance standards website is the authoritative reference for refrigerant handling documentation requirements in Australia.
Did You Know? The refrigerant handling documentation requirement under ARCtick isn't just about the quantity recovered. It covers the refrigerant type, the equipment it was recovered from, the cylinder it was recovered into, and who performed the work. Keeping thorough records protects your licence and simplifies any audit or compliance review.
Next Steps: System Evacuation
Once recovery is confirmed complete and the system is isolated, the next step in the workflow is evacuation. A thorough vacuum pull-down removes moisture and non-condensables from the system before recharging, and it's the other side of the same compliance and quality standard that makes recovery mandatory.
A system that goes from recovery straight into repair work and then directly to recharge, without a proper evacuation in between, will have poorer long-term performance and a higher risk of moisture-related compressor damage. The vacuum pumps collection at HVAC Shop covers the full Mastercool vacuum pump range to complete this next step with the right equipment.
For a broader understanding of the Mastercool recovery machine range and how to select the right model for your work, the Mastercool recovery machine series at HVAC Shop covers the MC69000 through MC69400 models with full specification detail.
Frequently Asked Questions: Using a Mastercool Recovery Machine
If you have questions about the right Mastercool machine for your job type, or want to confirm current stock and trade pricing, our team at HVAC Shop works with Australian HVAC-R contractors every day. View the full Mastercool range at HVAC Shop or get in touch directly.