Quick answer: A transport refrigeration unit in a delivery van or truck should be serviced every 6 months. A full 12-monthly service adds refrigerant system pressure testing, belt replacement on direct drive units, and temperature controller calibration. Units that skip scheduled service typically fail during the highest-demand periods — summer peak and pre-Christmas delivery season
A transport refrigeration unit that fails mid-route costs far more than a service. Lost cargo, missed deliveries, emergency call-out fees, and potential compliance penalties all exceed the cost of regular preventive maintenance. The checklist below is the same schedule Auto Frigo provides to customers after every new installation.
Why the 6-month interval matters
The 6-month service interval for transport refrigeration units is not arbitrary. A delivery van refrigeration unit running 5 days a week accumulates approximately 1,200 to 1,500 operating hours per year. Condenser coils in urban environments collect road dust, exhaust particulate, and insect debris that reduces heat transfer efficiency within 500 to 600 hours of operation. Under FSANZ Standard 3.2.2, food businesses have an obligation to maintain transport equipment in a condition fit for purpose. A unit that cannot hold setpoint because of infrequent service is a compliance failure, not just a mechanical one.
6-monthly service checklist
Every 6-monthly service on a transport refrigeration unit should include all items on this list. If a quote or service record does not cover these tasks, ask why.
| Task | Why It Matters |
|---|---|
| Check refrigerant level and inspect for leaks | Refrigerant loss is gradual; early detection avoids complete cooling failure |
| Clean condenser coils (wash and inspect fins) | Blocked coils reduce cooling capacity and overload the compressor |
| Inspect evaporator coils for ice buildup | Heavy ice points to a defrost fault or door seal failure |
| Inspect door seals — full perimeter check | A failed seal is responsible for a high proportion of temperature breaches |
| Check and clean the condensate drain line | A blocked drain causes water pooling and evaporator ice buildup |
| Check drive belt tension and condition (direct drive) | A worn belt slips or snaps, stopping the compressor |
| Check all electrical connections and fuses | Corroded connections cause intermittent faults that are difficult to diagnose |
| Test unit reaches and holds required setpoint | Confirms the system is operating correctly before the vehicle returns to service |
| Verify temperature alarm function | An alarm that does not activate on a breach gives no warning of cargo loss |
| Check compressor oil level (self-powered units) | Low oil causes compressor wear and premature failure |
12-monthly service: additional tasks
The 12-monthly service includes all 6-monthly tasks plus:
Full refrigerant system pressure test to identify micro-leaks not visible at 6 months
Drive belt replacement on direct drive units, regardless of visual condition
Door hinge and latch lubrication and alignment check
Temperature controller calibration verification against a certified reference thermometer
Insulation panel inspection for moisture ingress, delamination, or impact damage
Full wiring harness inspection for chafing, corrosion, and connector condition
Condenser and evaporator fan blade inspection for cracks or imbalance
For multi-temperature systems, the 12-monthly service also includes bulkhead seal inspection and separate temperature controller calibration for each zone.
Driver checks between services
The following checks take less than 5 minutes and should be carried out by the driver at the start of each shift. These are not replacements for a professional service, but they catch developing faults before they become breakdowns.
Before loading: confirm the unit has pre-cooled the cargo space to within 2°C of setpoint.
At each stop: confirm the cab temperature display is holding within 1°C of setpoint.
End of shift: listen for any new noise from the unit. Report immediately, not at next service.
Weekly: visually inspect the condenser unit for visible debris accumulation and check door seals for cracks or hardening.
How long do transport refrigeration units last?
A properly maintained direct drive unit in a metropolitan delivery van lasts 8 to 12 years. Self-powered units on long-haul trucks are typically overhauled at 10,000 to 12,000 engine hours. The single biggest factor in reaching the upper end of that range is consistent 6-monthly servicing.
Units that skip service intervals typically show compressor wear at 5 to 7 years, condenser damage from accumulated debris, and door seal failure that goes undetected until a temperature breach. The difference in total lifetime cost between a well-maintained and a poorly maintained unit is significant.
Auto Frigo provides 6-monthly and 12-monthly service plans for van and truck refrigeration units at both Melbourne workshops. For fleet operators with multiple vehicles, fixed-price service agreements are available. Book a service online or call 0486 023 788 to arrange a schedule.
Frequently Asked Questions
Can any refrigeration technician service a transport refrigeration unit?
Legally, any work involving refrigerant requires an ARCtick licence from the Australian Refrigeration Council. Beyond the legal requirement, transport refrigeration units have vehicle-specific installation requirements that differ from stationary systems. A technician experienced with building refrigeration may not be familiar with the compressor types, belt drive configurations, or electrical integration specific to transport units. Auto Frigo technicians work exclusively on transport refrigeration.
What happens if I miss a 6-monthly service?
Missing one service does not cause immediate failure. The risk is cumulative. Condenser coils become progressively more blocked, refrigerant loss goes undetected longer, and developing belt or seal wear is not caught. The units most likely to fail in the middle of peak summer delivery season are those that went through the previous summer without a service.
