When a Dometкм rv air conditioner is experiencing an issue, most of us are tempted to request a service engineer visit. However, it is not always necessary. In case of a minor malfunction you may diagnose the problem by an error code. Check for the error codes on the display or identify the symptom and look for an explanation and troubleshooting tips in the tables below.
| FAULT | POSSIBLE REASON | CORRECTION |
| Nothing works at all | Air conditioner circuit breaker is off. | Turn circuit breaker on at ship’s panel. |
| Wiring at terminal strip is incorrectly wired | Check wiring diagram; correct if necessary | |
| Fan runs but no water flow | Water intake valve is closed | Open valve |
| Strainer or intake is plugged | Clean strainer/intake | |
| Hose collapsed, kinked or pinched | Repair/reroute hose | |
| Pump relay panel may not be operating properly | Check pump relay panel wiring diagram. With unit breakers and A/C pump breaker on, check input voltage to relay panel. If voltage is not present, a wiring problem exists back to the ship’s panel. With unit on, check voltage at signal terminals (1A & IB, 2A & 2B, etc.) If voltage is not present, a wiring problem exists back to the unit. With voltage present at both locations above, check output terminals to seawater pump. If voltage is not present, either: 1. Signal circuit is defective. Move to a spare circuit if available. 2. Triac is defective on seawater pump circuit. | |
| Replace circuit board if above does not correct problem | ||
| Fan and Pump run, but no cooling or heating | Selector switch may not be in “Run” position, but rather in “Start” mode | Verify switch setting |
| Compressor not running or trying to start | Thermostat may not be set properly, thus not signaling compressor to start. | Turn counter-clockwise for warmer and clockwise for cooler |
| Wiring terminal to thermostat or selector switch may be disconnected. | Check wiring schematic before reconnecting loose terminals. | |
| Fan and Pump run, but no cooling or heating | Seawater intake valve may be closed. | Open valve |
| Compressor operates for only short periods of time. | Seawater strainer or intakes could be plugged. | Check hoses from intake to pump, pump to condensing unit, and condensing unit to overboard to make certain that they have not collapsed, pinched, or kinked. |
| Water pump may be defective. | Check voltage to pump, check pump head and impeller. | |
| Fan blows, Pump & Compressor runs, but unit does not heat or cool enough. | Dirty return air filter | Clean filter |
| Check for proper thermostat setting | Turn counter-clockwise for warmer and clockwise for cooler | |
| On heat setting, system takes fifteen minutes to stabilize. As the seawater becomes colder, the output of the system is reduced. Note that 45°F (7.2°C) seawater is the coldest recommended operating level. | Give system time to stabilize. Verify seawater temperature. | |
| On cooling, the thermostat may be set too cold or supply air may be short cycling causing the evaporator coil to freeze | Check thermostat setting and/or redirect supply air so that it is not directed into the return air stream. | |
| Switch unit into heat until the ice melts. A unit low on refrigerant charge will cause evaporator icing. | ||
| Low voltage can cause the air conditioning system to cycle off before proper temperature is reached | Check electrical supply source | |
| Reduced water flow | Visually check water flow overboard and if low take corrective action |
| Code | Description |
| E1 | Loss of communication between the CCC 2 thermostat and an individual system power module board. The LED will display error code EI and the zone number that lost communication. Any additional zones that loose communication will blink in addition to the current zone. |
| E2 | Open circuit or out-of-range indoor temperature sensor. All heat , cool, and dehumidify operations will be locked out. Manual fan operation will continue. |
| E3 | Shorted Indoor Temperature Sensor. All heat, cool, and dehumidify operation will be locked out. Manual fan operation will continue. |
| E4 | Open circuit or out of range Outdoor Temperature Sensor (select models). Heat pump and dehumidification operation will be locked out. Air conditioner, furnace, heat strip and fan operation can continue to operate. |
| E5 | Open circuit or out of range Freeze Sensor. Air conditioner and dehumidification operation will be locked out. Heat pump, furnace, heat strip and fan operation can continue to operate but displays the last temperature set-point. |
| E6 | Open circuit Humidity Sensor (Select Models). Air conditioner and dehumidification will be locked out. Heat pump, furnace heat strip and fan can continue to operate. |
| E7 | Loss of 120 VAC power to all power module boards on the system. The system will shut down. |
| E8 | Invalid zone configuration. The heat pump and heat strip DIP switches are both set to the ON position in one zone. Heat pump, heat strip, air conditioner, and dehumidify operation will be locked out in the affected zone. |
| E9 | Invalid zone configuration. The dehumidifier DIP switch and either the heat pump or heat strip DIP switches are set to the ON position in one zone. Heat pump, heat strip, air conditioner, and dehumidify operation will be locked out in the affected zone. |