Reefer not holding temp
Can I keep driving?
Check that the unit is running and the fuel is above a quarter, read the box temperature and the set point, then call dispatch. Use the list below to get the earliest reefer tech, mobile first.
Do this first
- Is the unit running, and on what? Look at the display. An alarm code, a shutdown message, or a unit that has gone quiet is one problem; a unit running flat out and losing ground is another. Check the reefer fuel; a quarter tank on a slope can starve the unit. Check that it is in continuous run rather than start-stop cycle if the load requires it.
- Read the code and the temperatures. Note the alarm code exactly as shown, the set point, the return air and the discharge air temperatures. Discharge air far below return air means the unit is cooling and the box is losing it through the doors or the walls. Discharge air near return air means the unit is not cooling.
- Walk the box. Doors sealed and latched, door gaskets intact, the air chute not torn or blocked, the load not stacked against the evaporator or blocking the return. The evaporator coil not iced over. Many "reefer not holding" calls are a door seal or a blocked airflow and need no tech at all.
What it usually costs and how long it takes
From no-cost to serious:
- Fuel, a door seal, a blocked chute, or a defrost. Free or close to it, fixed where you stand.
- Sensor, belt, fuel filter or a minor electrical fault. Mobile reefer techs carry these. The alarm code usually says which.
- Refrigerant leak, compressor, or a failed engine on the unit. Dealer-level. A leak has to be found and repaired before the unit is recharged, and a compressor can be a multi-day repair.
- Rescue reefer or a cross-dock. When the fix is slower than the load's clock, the cheapest answer is sometimes moving the product, not repairing the unit on the road. Dispatch makes that call; give them the numbers.
The unit's brand matters here more than on any other page: Thermo King and Carrier units are serviced by their own dealer networks, with the software and the parts, and the list below marks which is which.
Where to get it fixed
Reefer service follows the dealer networks rather than general truck repair. Cities where reefer-capable supply is deepest:
Frequently Asked Questions
The unit is running but the box keeps warming. Is it broken?
Not necessarily. If discharge air is cold and return air is warm, the unit is working and the box is losing heat through the doors, the seals, a torn chute, or a load stacked against the evaporator. Fix the airflow and the box usually recovers. If discharge air is not cold, the unit is the problem.
How long does the load have?
That depends on the product, the set point, the outside temperature and how full the box is. A full load of frozen product in a sealed box drifts slowly; a half load of produce in summer does not. Give dispatch the numbers and let them talk to the receiver.
Can any truck shop work on a reefer?
Mostly no. Reefer units are their own engine, their own refrigeration circuit and their own electronics, serviced by Thermo King and Carrier dealer networks and a smaller number of independent reefer specialists. A general shop can do fuel and belts; anything on the refrigeration side needs a reefer tech.
The unit shut down with an alarm code. Can I restart it?
Some codes clear on a restart and the unit runs; some will shut it down again immediately. Try one restart, note the code, and do not keep cycling it; repeated restarts on a low-oil or high-pressure alarm damage the unit.
Does it matter whether it is on cycle or continuous?
Yes, for some loads. Cycle-sentry saves fuel but lets the temperature swing; produce and some pharmaceuticals require continuous run. If the load papers say continuous and the unit is on cycle, that alone can explain a temperature excursion.
Should I open the doors to check the load?
Only if you have to. Every door opening lets in warm, moist air that the unit then has to remove. Check the readout and the seals first.
- The unit is running but the box keeps warming. Is it broken?
- Not necessarily. If discharge air is cold and return air is warm, the unit is working and the box is losing heat through the doors, the seals, a torn chute, or a load stacked against the evaporator. Fix the airflow and the box usually recovers. If discharge air is not cold, the unit is the problem.
- How long does the load have?
- That depends on the product, the set point, the outside temperature and how full the box is. A full load of frozen product in a sealed box drifts slowly; a half load of produce in summer does not. Give dispatch the numbers and let them talk to the receiver.
- Can any truck shop work on a reefer?
- Mostly no. Reefer units are their own engine, their own refrigeration circuit and their own electronics, serviced by Thermo King and Carrier dealer networks and a smaller number of independent reefer specialists. A general shop can do fuel and belts; anything on the refrigeration side needs a reefer tech.
- The unit shut down with an alarm code. Can I restart it?
- Some codes clear on a restart and the unit runs; some will shut it down again immediately. Try one restart, note the code, and do not keep cycling it; repeated restarts on a low-oil or high-pressure alarm damage the unit.
- Does it matter whether it is on cycle or continuous?
- Yes, for some loads. Cycle-sentry saves fuel but lets the temperature swing; produce and some pharmaceuticals require continuous run. If the load papers say continuous and the unit is on cycle, that alone can explain a temperature excursion.
- Should I open the doors to check the load?
- Only if you have to. Every door opening lets in warm, moist air that the unit then has to remove. Check the readout and the seals first.
This page is general guidance for professional drivers and is not a diagnosis of your refrigeration unit. Load temperature requirements are set by the shipper and the receiver; follow your dispatch instructions and keep the temperature log. Shop listings are provided by Trucker Path users and the businesses themselves; availability and pricing are confirmed by the shop, not by Trucker Path.