TravelCool Learning Center

TravelCool Error Codes and Troubleshooting Guide

A TravelCool error code identifies the protection or fault category reported by a particular display. It does not, by itself, authorize an owner to open the rooftop unit, repair wiring or enter the R-32 refrigerant circuit.

First identify where the code appears. The TravelCool interior unit display and the optional MRDCW wired wall controller use different code lists, and the same letters can mean different things on those two interfaces. Record the complete code and the display that showed it before contacting service.

Do not use a generic MRCOOL error-code list. TravelCool has model-specific tables. For example, E6 and E7 do not have the same descriptions on the main TravelCool display and the MRDCW controller.

Safe first response to an MRDCW code

The MRDCW Wired Controller Manual gives this sequence when a controller code appears:

  1. Turn the unit off and disconnect power.
  2. Wait 10 seconds.
  3. Restore power and turn the unit on.
  4. If the code disappears, continue observing operation.
  5. If the code persists, turn the unit off, disconnect power and contact maintenance.

Do not repeatedly reset a persistent code. A recurring protection event needs model-specific diagnosis, not repeated power cycling.

TravelCool main-unit display codes

The following descriptions come from the TravelCool Installation & Owner's Manual. They apply to the TravelCool unit display, not automatically to MRDCW.

Code Official fault or protection description Manual handling summary
E1 / E2 / E5 Indoor pipe temperature sensor fault Indoor unit may run while the outdoor unit stops; operation may restore after reset or recovery.
E6 Outdoor coil temperature sensor failure Indoor unit may run while the outdoor unit stops; operation may restore after reset or recovery.
E7 Exhaust temperature sensor failure Indoor unit may run while the outdoor unit stops; operation may restore after reset or recovery.
E8 Indoor fan motor failure The unit stops and requires troubleshooting.
E9 Outdoor fan motor failure The outdoor unit stops and requires troubleshooting.
F0 Exhaust temperature protection The outdoor unit stops and may resume after the condition is resolved.
F2 AC overcurrent protection The unit shuts down; the manual identifies a reboot response.
F3 Compressor phase overcurrent protection The unit shuts down; the manual identifies a reboot response.
F4 DC bus overvoltage protection The unit shuts down; the manual identifies a reboot response.
F5 DC bus undervoltage protection The unit shuts down; the manual identifies a reboot response.
F6 AC undervoltage protection The unit shuts down; the manual identifies a reboot response.
F7 Main-board/driver-board communication fault Indoor operation may continue while the outdoor unit stops.
F8 Main-board/display-board communication fault The unit shuts down; the manual identifies a reboot response.
H1 IPM over-temperature protection The outdoor unit stops and may resume after troubleshooting.
H2 Compressor starting fault, phase loss or incorrect phasing The unit shuts down; the manual identifies a reboot response.
H3 IPM module failure The outdoor unit stops and requires troubleshooting.
H4 Compressor out-of-step or stalling failure The outdoor unit stops and requires troubleshooting.
C2 Outdoor low-temperature safeguard for heating The unit halts and restarts after outdoor temperature normalizes.

MRDCW wired-controller codes

These descriptions come from the separate MRDCW Wired Controller Manual. They apply when the code is shown on the optional MRDCW controller.

Code Official MRDCW description
Eb Communication fault between the wired controller and main board, or between the LCD and main board.
E0 Indoor EEPROM fault.
E1 Indoor/outdoor communication fault.
E3 Indoor fan motor stall fault.
E6 Water-full fault associated with the drain pump.
E7 Outdoor fan motor stall fault.
E11 Neutral and live wires reversed.
E12 Phase-sequence reversal fault.
E13 Compressor low-pressure fault.
E51 Outdoor EEPROM fault.
E52 Outdoor condenser sensor (T3) fault.
E53 Outdoor ambient-temperature sensor (T4) fault.
E54 Outdoor discharge-sensor fault.
E60 Indoor ambient-temperature sensor fault.
E61 Indoor evaporator-temperature sensor (T2) fault.
E6A Indoor evaporator-temperature sensor (T2B) fault.
P43 Phase-loss protection.
P81 Outdoor overcurrent protection.
PB Compressor low-pressure protection.
PC Compressor high-pressure protection.
PL Refrigerant-leak fault.

Information to collect before requesting service

  • The complete code exactly as displayed.
  • Whether it appeared on the interior TravelCool display or MRDCW.
  • The rooftop, ceiling-assembly and controller model numbers.
  • What operating mode was selected when the code appeared.
  • Whether the code cleared after the single documented power reset.
  • Any visible obstruction, damage, water staining, odor or unusual sound.
  • The electrical source in use, without guessing at the cause.

Do not purchase a rooftop unit, controller, sensor or other replacement part solely because a code mentions that subsystem. A qualified diagnosis may identify wiring, communication, power, airflow, temperature or another condition instead of a failed retail component.

When to leave the system off

Disconnect power and obtain qualified service when a code persists, wiring or the housing is damaged, a breaker repeatedly opens, water is present where it should not be, or refrigerant-circuit work may be required. TravelCool uses R-32 refrigerant, and refrigerant service requires appropriately qualified personnel and suitable safety procedures.

Use the manual for the exact display

Use the TravelCool Installation & Owner's Manual for main-unit codes and the MRDCW Wired Controller Manual for controller-specific codes and reset instructions.

Confirm the model before ordering a part

After diagnosis, use the governed TravelCool component relationships to find the correct replacement rooftop, ceiling assembly or control.

Find TravelCool parts and controls or review the TravelCool maintenance guide.