Dometic E3 fault code — Thermostat
Applies to: Single Zone LCD thermostat, 3313192, 3313193, 3313194
What E3 means
The Dometic Single Zone LCD thermostat manual lists E3 as a shorted indoor temperature sensor; heating and cooling operation lock out while fan operation can continue.
Owner-safe checks
- Record the E3 code, room temperature, mode, fan setting, and setpoint.
- Use only normal thermostat controls to turn off heat or cooling if the coach is uncomfortable.
- Note whether fan-only operation continues before calling service.
Service-only work
- Indoor temperature sensor and thermostat circuit diagnosis should be handled by qualified RV HVAC service.
Safety boundary
Do not open thermostat, rooftop HVAC, or electrical compartments, and do not bypass communication or sensor circuits. Shut the affected HVAC system off and arrange qualified RV HVAC service for unresolved Single Zone LCD faults.