Dometic CCC 2 thermostat codes and reset

A Dometic CCC 2 error code identifies a communication, sensor, power or configuration condition, not a replacement part. Record the code and blinking zone before a reset. These meanings and the MODE/ZONE reset apply to the model 3314080 thermostat in Dometic’s Revision B instructions.

Read the code with the affected zone

The 2016 CCC 2 operating instructions distinguish a fault affecting one power module from a whole-system loss. A running fan does not establish that a locked-out heating or cooling mode is available.

CCC 2 Revision B code interpretation
CodeMeaningEffect described by the maker
E1Module communication lostAll boards: system stops; individual board: affected zone identified
E2 or E3Indoor sensor open/out of range or shortedHeating/cooling locked; manual fan available
E4Outdoor sensor fault on applicable equipmentHeat pump locked; other listed modes remain
E5Freeze sensor faultAC locked; other listed modes remain
E7120 V AC lost at all power modulesSystem stops
E8Heat-pump and heat-strip configuration conflictAffected-zone heat pump, heat strip and AC locked
E9Dehumidifier/configured-heat conflictAffected-zone heat pump, heat strip and AC locked

Use initialization for the condition it addresses

For the covered CCC 2, the reset starts with the thermostat OFF: press MODE and ZONE together until IniT and the available zones appear, release them, and press ON/OFF to exit. Initialization restores factory settings. It cannot repair missing supply power or a defective sensor.

Photograph the indication and record previous schedules first. A missing zone after initialization is useful service evidence. Do not open a powered rooftop control box or change configuration switches to make a code disappear.

Preserve the CCC 2 fault informationPhotograph the code and blinking zoneThen: Match model 3314080 and the installed equipmentThen: Use documented controls or arrange qualified diagnosisPreserve the CCC 2 fault informationPhotograph the code and blinking zoneMatch model 3314080 and the installed equipmentUse documented controls or arrange qualified diagnosis

Distinguish a delay from a fault

A cooling request need not produce an immediate compressor start. Look for the compressor-delay indication and allow the matching system’s delay. Do not switch it repeatedly while deciding whether it works.

Check whether the selected zone and mode match the equipment fitted to the RV. A thermostat displaying a mode is not proof that an optional appliance exists. If the whole screen is unlit, check the documented wake-up control before concluding that it has lost power.

Give service the thermostat and appliance identities

Record the thermostat model, the rooftop-unit label and any accessible control-kit identification. Explain whether one zone or every zone failed and whether it happened after a power interruption or equipment change. This separates a zone-specific symptom from a supply problem.

For airflow, icing or warm-air observations without a CCC 2 error, use the rooftop air-conditioner guide. For breakers or absent shore power, use the dead outlets and tripping breakers. Avoid assuming that a thermostat reset resolves either problem.