Reefer Won't Pull Down? Troubleshoot It Before the Load Cooks
Nothing sharpens the mind like $60,000 of produce warming up behind you. Before you make the panicked call, run this list — half of all reefer emergencies are one of the first three checks, and the clock cares about minutes, not drama.
The first three checks (solve most panics)
- Fuel. The reefer has its own tank, and "reefer's dead" is diesel-for-empty in a startling share of cases — the unit shuts down or falters long before the truck's gauges care. Check it first, feel silly privately, move on gratefully.
- Setpoint and mode. Confirm the setpoint matches the BOL — a fat-fingered 35 instead of -5 is a career-memorable mistake — and check the run mode: Cycle-Sentry (start/stop, fuel-saving) is fine for hardy freight but lets temps wander; continuous is what produce, meat, and anything sensitive wants. Wrong mode reads exactly like a weak unit.
- Is it in defrost? A reefer mid-defrost blows warm on purpose and resumes cooling after. If the coil looks like a snow cone — common in humid loading docks with doors held open — run a manual defrost and give it time; an iced coil can't move cold air no matter how healthy the machine is.
The next tier: airflow and honesty about the load
- Airflow is the unit's circulatory system. Check the bulkhead isn't blocked, the air chute isn't torn or collapsed, and the load isn't stacked to the ceiling against the rear doors. A reefer cools by circulating; freight loaded like a wall turns the front pallets into insulation for the back ones.
- Door seals and door discipline — daylight through a seal is warm air on retainer.
- Was the load warm going in? The uncomfortable one: a reefer is built to hold temperature, not to chill a hot load down — pulping the freight at pickup exists precisely for this fight. A unit "failing" to pull a warm load down isn't failing; it's doing physics. This is also why you pre-cool the box before loading, every time, and why the pulp reading at the dock is your legal alibi later.
When it's genuinely the machine
Unit codes on the display (photograph them), short-cycling, alarms, a compressor that runs without the temperature responding — now it's a service call, and reefer work is its own trade: call refrigeration-capable service, not a general truck shop. Expect a mobile reefer call around $300–$600 plus parts; against a rejected load claim, that's the cheapest number in this article.
While you wait: keep the doors shut — every peek costs cold you can't spare — note temps and times as you go (claims run on documentation), and call the broker/shipper early if the load's at risk. A problem reported at 2° of drift is a conversation; reported at 20° it's a courtroom.
Reefer trouble on top of truck trouble? The breakdown checklist handles the tractor side — and its advice about mentioning the reefer clock in every call goes double when the freight is the emergency.
Unit's genuinely down?
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Quick answers
What do I check first when a reefer won't hold temp?
Fuel level, set point and mode (continuous vs. cycle-sentry), alarm codes on the display, and airflow — a badly loaded box or blocked bulkhead can look exactly like a refrigeration failure.
When do I call reefer service?
The moment a temp-sensitive load stops pulling down toward set point. Produce and protein don't wait, and a rejected load costs more than any service call.
What does reefer service cost?
Comparable to other mobile service — a call-out fee plus hourly labor, with parts on top. Thermo King and Carrier dealers cost more but carry the parts that fix it the first time.