Dometic Harrier
Official technical documentation and workshop diagnostics for Harrier.
Technical Specifications
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|
N/A | Roof air conditioner constantly switches itself off Possible Cause: Icing sensor has tripped. Outer temperature is too low or all air nozzles are closed. | Check ambient temperature and ensure air nozzles are open. | DIY Safe |
N/A | Roof air conditioner constantly switches itself off. Possible Cause: Icing sensor has tripped because outer temperature is too low or all air nozzles are closed. | Ensure outer temperature is within operating limits and open air nozzles. | DIY Safe |
N/A | Not cooling well Possible Cause: The roof air conditioner is not set to cooling, ambient temperature is above 52 °C or below 16 °C, set temperature is higher than room temperature, or temperature sensor/fans are defective. | Set unit to cooling, ensure ambient temperature is between 16 °C and 52 °C, select a lower temperature, or contact an authorised service agent if components are defective. | DIY Check / Tech Fallback |
N/A | Not heating well Possible Cause: The roof air conditioner is not set to heating, ambient temperature is below –2 °C, set temperature is lower than room temperature, or temperature sensor/fans are defective. | Set unit to heating, ensure ambient temperature is above –2 °C, select a higher temperature, or contact an authorised service agent if components are defective. | DIY Check / Tech Fallback |
N/A | Low air output Possible Cause: Air intake grilles are blocked or obstructed, or fan is defective. | Remove leaves and other dirt from the ventilation grilles. Contact an authorised service agent if fan is defective. | DIY Check / Tech Fallback |
N/A | Water enters the vehicle Possible Cause: Condensation water drainage openings are clogged up or seals are damaged. | Clean the drainage openings for condensation water or contact an authorised service agent to replace damaged seals. | DIY Check / Tech Fallback |
N/A | Roof air conditioner does not switch on Possible Cause: No supply voltage (240 V AC) connected, voltage too low (under 200 V AC), defective voltage converter/temperature sensor, or electrical fuse of power supply is too low. | Check power supply and electrical fuse. Contact an authorised service agent if voltage is under 200 V AC or internal components are defective. | DIY Check / Tech Fallback |
N/A | Roof air conditioner does not switch on. Possible Cause: No supply voltage connected, voltage too low (under 200 Vw), defective voltage converter, defective temperature sensor, or electrical fuse of the power supply is too low. | Check power supply and electrical fuses, ensure voltage is above 200 Vw, or contact an authorised service agent for converter/sensor faults. | DIY Check / Tech Fallback |
N/A | Roof air conditioner does not switch off Possible Cause: One of the temperature sensors is defective or electrical fuse rating is incorrect. | Check the electrical fuse of the power supply or contact an authorised service agent. | DIY Check / Tech Fallback |
N/A | Roof air conditioner does not switch off. Possible Cause: One of the temperature sensors is defective or electrical fuse rating is incorrect. | Check power supply fuse or contact an authorised service agent to replace the defective temperature sensor. | DIY Check / Tech Fallback |
N/A | Remote control does not register Possible Cause: Remote control is not pointing towards the air outlet unit display, or batteries are empty. | Point the remote control towards the air outlet unit display or replace batteries (2x type AAA). Note that the remote display can remain bright even when batteries are low. | DIY Safe |
N/A | [Mechanical/Water] Water enters the vehicle Possible Cause: Condensation water drainage openings are clogged up or seals are damaged | Clean the drainage openings for condensation water or contact an authorised service agent to replace damaged seals. | DIY Check / Tech Fallback |
N/A | [230V AC] Roof air conditioner does not switch on Possible Cause: No supply voltage connected, voltage too low (under 200 V AC), defective voltage converter, defective temperature sensor, or electrical fuse of power supply is too low | Check power supply and electrical fuses, or contact an authorised service agent for internal voltage converter/sensor issues. | DIY Check / Tech Fallback |
N/A | [230V AC] Roof air conditioner does not switch off Possible Cause: One of the temperature sensors is defective or electrical fuse rating is incorrect | Contact an authorised service agent or check electrical supply fuse. | DIY Check / Tech Fallback |
Frequently Asked Questions
Q: MY ROOFTOP UNIT HAS THE ELECTRIC HEAT STRIP OPTION (NON-HEAT PUMP ELECTRIC HEAT OPTION), BUT WHEN IT GETS COLDER OUTSIDE IT DOESN’T SEEM TO MAINTAIN THE TEMPERATURE. WHAT SHOULD I DO?
Electric heat strips are designed to take the chill out of the air inside your motorhome, but they are not intended to be the primary heat source for cold weather camping. When outdoor temperatures drop significantly, the heat loss of the motorhome typically exceeds the capacity of a standard electric heat strip.
Q: WHAT ARE THE BENEFITS OF A MOTORHOME AIR CONDITIONER?
An motorhome air conditioner helps maintain a comfortable indoor climate, reduces humidity levels inside the vehicle, and filters out dust and pollen, creating a more pleasant and healthy living space while traveling or camping.
Q: WHAT IS THE IDEAL AIR CONDITIONING TEMPERATURE?
The ideal indoor air conditioning temperature for an motorhome is generally between 70°F and 72°F (21°C to 22°C), balancing comfort and energy efficiency.
Q: WHAT MOTORHOME AC DO I NEED IN WARM LOCATIONS?
For extremely warm locations or larger motorhomes, a high-capacity rooftop air conditioner (such as a 13,500 BTU or 15,000 BTU unit) or a dual AC setup is recommended to adequately cool the space.
Q: HOW DOES MOTORHOME AIR CONDITIONING WORK?
Motorhome air conditioning works on the same principle as a standard home AC unit. It uses a refrigeration cycle involving a compressor, condenser, expansion valve, and evaporator to absorb heat from the interior air and exhaust it outside, while blowing cooled air back into the motorhome.
Q: HOW TO RUN MY MOTORHOME AC WITH A GENERATOR?
To run your motorhome air conditioner with a generator, ensure the generator has sufficient running and starting wattage (surge wattage) to handle the compressor's startup load—typically a minimum of 2,000 to 3,000 watts depending on the AC unit size. Always start the generator and let it stabilize before turning on the air conditioner.
Q: HOW TO RUN MY MOTORHOME AIR CONDITIONER ON THE CAMPSITE?
To run your motorhome air conditioner at a campsite, connect your motorhome to an appropriate power pedestal (usually 30-amp or 50-amp service) matching your motorhomes electrical system requirements. Ensure other high-draw appliances are managed to avoid tripping the campsite breaker.