Confirm the model before installing
This procedure applies to Dometic Single Zone LCD thermostats 3313192, 3313193, and 3313194. If the thermostat is not one of these models, stop and use its own manual.
Initialize the thermostat
| Step | Action | Stop |
|---|---|---|
| 1 | Put the thermostat in the Off condition. | Stop if the display will not turn off. |
| 2 | Press and hold +, then press and hold On/Off Mode for three seconds. | Stop if the LCD does not show –. |
| 3 | Press On/Off Mode again to turn the system off; initialization is complete. | Stop if the display does not clear. |
Set the furnace differential
The system can use a 1 F or 2 F On/Off differential. With the system Off, press and hold -, then press and hold On/Off Mode for three seconds; release On/Off Mode, then release -. Press + to toggle between d1 (1 F) and d2 (2 F). Choose d2 for the factory default.
Review the factory presets
| Setting | Factory preset |
|---|---|
| Heating | 68 F / 20 C |
| Cooling | 72 F / 22 C |
| Fan speed | Auto |
| Mode | Off |
| Furnace differential | 2 F |
Stop conditions
- E1: loss of communication between the thermostat and the module board; the system shuts down.
- E2: open circuit or out-of-range indoor temperature sensor; heating and cooling lock out.
- E3: shorted indoor temperature sensor; heating and cooling lock out.
- Any repair beyond these checks must be done by qualified service personnel.
Source: Dometic Single Zone LCD Thermostat Operating Instructions, Form 3313327.045.
Diagnose before replacing
| Check | Meaning | Stop |
|---|---|---|
| Power source | Generator running or land line connected and producing power. | Stop if no power. |
| 12 Vdc fuse | Fuse or circuit breaker open. | Stop if blown or repeatedly open. |
| E1 | Loss of communication with the module board. | Stop and inspect the connection. |
| E2 | Open or out-of-range indoor temperature sensor; heating and cooling lock out. | Stop for sensor service. |
| E3 | Shorted indoor temperature sensor; heating and cooling lock out. | Stop for sensor service. |
If the fault remains after the power and fuse checks, call qualified service personnel; do not keep replacing the thermostat.
Replacing the thermostat
| Step | Action | Stop |
|---|---|---|
| Model match | Confirm the replacement is 3313192, 3313193, or 3313194 and matches the old unit. | Stop if the model is incompatible. |
| Remove and install | Remove the old thermostat, install the replacement, and restore power. | Stop if the wiring or module board is unknown. |
| Initialize | With the thermostat Off, hold + and On/Off Mode for three seconds, wait for –, then press On/Off Mode again. | Stop if the display does not initialize. |
| Differential | Hold – and On/Off Mode for three seconds, release, then press + to choose d1 or d2. | Stop if the differential will not change. |
| Presets | Review heat 68 F, cool 72 F, fan Auto, mode Off, differential 2 F. | Stop if the presets are wrong. |
Stop if E1, E2, or E3 appears after replacement. Use qualified service personnel for any repair beyond these checks.