Used Reefer Container Inspection Checklist

Most container inspection advice is written for dry boxes: check for rust, check the floor, check the doors. All of that applies to a reefer, but it covers roughly half of what you're buying. A refrigerated container is an insulated steel box with a refrigeration machine attached, and those two components age independently.

A structurally perfect box with a tired compressor is a bad buy. So is a healthy unit bolted to a box whose insulation has been compromised, because the machinery will run itself ragged fighting heat ingress it can never win against. Inspect both, and treat a serious problem in either as disqualifying.

Start outside. Surface rust in patches is normal on a used unit and largely cosmetic. What you're looking for is deep corrosion, rust that has gone through, and any large warped or buckled area — those affect structural integrity, and on a reefer they often signal an impact that also disturbed the insulation behind the panel.

Check the corner castings specifically. These are the reinforced steel corner fittings the container is lifted and secured by, and they need to be intact and free of cracks. Damaged castings are a safety issue for every future lift, not a cosmetic one, and they matter even if the container will never move again — because it has to be set down on your site at least once.

Inside, the floor should be solid, with no soft spots, holes, or significant staining from spilled cargo. On a reefer, also check the T-section floor channels that let air circulate underneath the load. If they're crushed or blocked, airflow is compromised and the unit cannot hold temperature evenly no matter how well the machinery works.

This one costs nothing and reveals more than any visual sweep of the exterior. Step inside, close the doors, and let your eyes adjust for a minute or two.

Any daylight visible — through door edges, roof seams, corner joints, or panel repairs — is a path for outside air. On a dry container that means water ingress. On a reefer it means the refrigeration unit is being asked to cool the outdoors, continuously, forever. Small light leaks that would be a minor annoyance on a storage box are a genuine operating-cost problem on a refrigerated one.

Door seals do more work on a reefer than on any other container type, and rubber is the component most predictably degraded by age and UV. Check the full perimeter for brittleness, cracking, tearing, and compression set — a seal that has flattened out and no longer springs back is no longer sealing, even if it looks intact.

Seals are replaceable, so a bad seal is a negotiating point rather than a walk-away. Insulation damage is the more serious concern, because it usually isn't. Look at exterior panels and interior sidewalls for patches, gouges, and evidence of previous impact repair. A neat repair on the outside tells you nothing about whether the insulation behind it was properly restored, and compromised insulation degrades thermal performance permanently.

If at all possible, see the unit run. A refrigeration unit under load should operate without abnormal noise, excessive vibration, visible oil leakage, or unstable pressure behaviour. Any of those signals a problem that a static inspection will not reveal.

Ask about service history, and specifically ask whether the unit has been running consistently or sitting idle. This is counterintuitive but reliable: a unit in continuous cold-chain service tends to have a more predictable condition than one that's been parked for two years, because regular operation surfaces faults and gets them fixed, while long idleness lets seals dry out and problems accumulate unnoticed.

Ask about recent work on the compressor and the door seals — the two components most likely to need attention on an older unit, and the two that most directly determine whether it holds temperature. If the unit will be used for regulated storage, confirm calibration and temperature-logging capability separately; not every reefer has a logging system fitted, and a working thermostat is not the same as an auditable temperature record.

Inspecting a container takes a trip. A ten-minute conversation first can save a wasted one, and the answers also tell you something about how straight the seller is being.

Ask for the unit's model designation and running hours. Ask when it last ran, and whether it can be run for you when you visit. Ask whether it's been in continuous service or stored idle, and for how long. Ask what work has been done recently, particularly on the compressor and seals. Ask whether the controller stores alarm history and whether you can see it.

Ask for photographs of specific things rather than general shots: the machinery end, the interior with doors closed and lights off if possible, the floor including the drainage channels, the door seals along their full length, and the data plate.

A seller who can answer these readily is describing a unit they know. One who deflects on running hours or can't say whether it's been running is either not close to the equipment or would rather you didn't ask — either way, adjust your expectations before spending a day travelling.

The single most valuable thing you can do is watch the unit operate. In the shipping world the formal version of this is a pre-trip inspection, where the unit is run through its functions and checked against expected behaviour. You may not get a full one, but you can observe a great deal from a straightforward run.

Watch the startup. The unit should start without excessive struggle and settle into steady operation. Listen for knocking, grinding, or irregular noises from the compressor, and watch for vibration beyond normal running.

Watch it pull down. A healthy unit should visibly move the temperature toward setpoint at a reasonable rate. Slow or stalled pull-down suggests a refrigerant, compressor, or airflow problem — and it's the symptom most likely to be hidden by only running the unit briefly.

Check that air is actually moving inside. Evaporator fans should run and you should feel airflow at the discharge. A unit that cools but doesn't circulate will not hold an even temperature under load.

Look for oil traces around the compressor and fittings, which indicate refrigerant leaks. Check the defrost cycle if you can — in humid climates it works hard and a failed defrost turns the evaporator into a block of ice.

If the unit cannot be run at all, treat that as a significant unknown and price it accordingly. "It ran fine when it was parked" is not information.

Confirm that the container's markings match what you're being sold. The data plate carries identifying information for the box, and the refrigeration unit has its own identification separate from the container's.

For a container that will ever move as freight, a valid CSC safety-approval plate matters, since that's what governs whether it can be shipped. For static storage it's less critical, but its absence or expiry is still something to know about rather than discover later.

Ask what documentation comes with the unit — service records above all. A unit with a documented service history is worth more than an identical one without, precisely because the history is the only reliable evidence of how it's been treated.

If the container is destined for offshore use, none of the above is sufficient on its own; offshore work requires certification to a different standard entirely, covered in DNV 2.7-1 explained.

An inspection isn't pass or fail. Most used units have something, and the useful output is an adjusted view of what the unit is worth to you.

Price the repairable findings. Door seals, filters, minor rust treatment, and cosmetic work all have knowable costs — get a rough figure and treat it as part of the purchase price rather than a grievance.

Price the lifespan findings differently. High running hours don't need repairing today; they shorten the runway before the repair-or-replace decision arrives. That's a discount on a working unit, not a fault to fix, and our guide to what a reefer container actually costs to own covers how to weigh it.

Walk away from the structural and machinery findings listed below. Those aren't negotiating positions — they're a different, worse purchase wearing the same price tag.

Worth negotiating on, not walking away from: patchy surface rust, dents that haven't broken through, worn paint, degraded door seals, minor floor wear.

Worth walking away from, or at minimum getting a refrigeration technician's opinion on before committing: cracked or damaged corner castings, rust perforation anywhere in the envelope, visible daylight in the light test, soft or holed flooring, crushed floor channels, and any refrigeration unit that won't run or runs with obvious mechanical distress.

If the grade terminology in listings is what's confusing you rather than the physical condition, container grades explained covers what Cargo Worthy, Wind & Water Tight, and One-Trip actually mean. For the wider buying picture, see the reefer container buying guide — and sort out electrical requirements before you commit, since that's the constraint that most often turns into a problem after delivery.