Refrigerated trailer service

Temp problems solved. Cold chain back on schedule.

Reefer unit diagnosis, compressor service, electrical repair, controller programming, and full refrigeration system work for fleet and owner-operator reefers.

Call (865) 525-1115 Request a quote

When a reefer trailer won't hold temp, every hour matters. Product is at risk, deliveries are at risk, the customer relationship is at risk. Knox Trailers diagnoses reefer problems fast — usually within an hour of arrival — and gets the unit working again. We service Carrier, Thermo King, and other major reefer brands. We carry common parts and have working relationships with the brand distributors for everything else.

Reefer work we handle

Reefer unit diagnosis

Cooling problem, temperature swing, alarm code, fuel issue, or unit won't start. Diagnostic computers for Carrier and Thermo King units. Quick, accurate read on what's actually wrong.

Compressor service and replacement

Compressor seal kits, valve plate service, full compressor replacement when needed. Common applications kept in inventory.

Refrigerant evacuation and recharge

R-404A, R-452A, and other refrigerant systems serviced per EPA Section 608 requirements. Proper evacuation, leak testing, and recharge to spec.

Electrical and controller repair

Wiring harnesses, sensors, contactors, fuses, batteries. Controller programming and parameter updates. APX-1, microprocessor displays, telematics integration.

Belt, fan, and condenser service

Drive belts, condenser fans, evaporator fans. Condenser cleaning. Charge air cooler service. Fan motor replacement.

Door seal and insulation work

Door gasket replacement, insulation patches, floor scoring, and structural fixes that affect temp retention.

Schedule the work or get a quote.

Mon–Fri 7am–6pm. Same-day appointments most weeks.

(865) 525-1115 Request a quote

What good looks like

When you bring a trailer to Knox Trailers, here's what you should expect.

Diagnosis within 60 minutes of arrival
Photos and explanation of the actual problem before any work starts
Most reefer repairs completed same-day for fleet customers
Refrigerant work documented per EPA Section 608
Pre-trip verification that the unit holds temp before you leave
Service records compatible with shipper compliance audits

Why shippers send reefers to us

Reefer work is specialty work. Most general trailer shops won't touch it because they don't have the diagnostic tools, the EPA certification for refrigerant work, or the technical training to work on Carrier and Thermo King units. We do.

We also understand the business side. A reefer that won't hold temp isn't just a mechanical problem — it's a relationship problem with your shipper. We work fast for that reason. Most repairs that other shops would schedule out a week, we knock out in a day.

Common questions

Do you service all reefer brands?

Carrier and Thermo King are our primary brands and we have full diagnostic capability. Other brands (Hwasung, Mitsubishi, smaller units) we can service for most common issues. Call us with the specific make and model and we'll confirm.

Are you EPA Section 608 certified for refrigerant work?

Yes. All refrigerant handling, evacuation, and recharge is done per EPA Section 608 requirements. We carry R-404A and R-452A in inventory.

What if my reefer is down and I'm not in Knoxville?

Mobile reefer service is available across our service area. We dispatch a service truck with diagnostic tools and most common parts. For longer distances, we'll get you triaged by phone and help arrange a closer shop.

Ready to get it fixed?

Same-day appointments most weeks for fleet customers. Call or request a quote and we'll get you scheduled.