Dometic Blizzard Turbo Split System
Official technical documentation and workshop diagnostics for Blizzard Turbo Split System.
Technical Specifications
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|
N/A | Unit does not operate at all. Internal fan (blower) is not running. Possible Cause: No AC power, tripped circuit breaker, disconnected or incorrect control wiring (e.g., SMXII logic board instead of Q-Power Logic Board), or dead batteries. | Turn on circuit breaker, ensure Qt Control is connected to Q-Power Logic Board, check CXP/TSEP cables and connections, ensure generator/shorepower/inverter is outputting correct power. | DIY Safe |
N/A | Unit does not make cold air. Possible Cause: Incorrect temperature setpoint, clogged evaporator air filter, switch not set to COOL, evaporator blower or condenser blower not running, or evaporator coil frozen up. | Adjust setpoint, clean or replace evaporator air filter, ensure switch is in COOL mode, check airflow from grilles and under sleeper, clean condenser coil, defrost frozen evaporator by turning off compressor and setting fan to maximum. | DIY Safe |
N/A | "LO" then "AC" (Low AC voltage shutdown) Possible Cause: Incoming AC line voltage is too low (<= 104VAC on 115V system, <= 207V on 230V system for > 3 minutes in COOL mode; <= 95VAC on 115V system, <= 200VAC on 230V system in HEAT mode). | Check AC line voltage calibration and verify power source output. | DIY Safe |
N/A | "HI" then "AC" (High AC voltage shutdown) Possible Cause: Incoming AC line voltage is too high (>= 127VAC on 115V system, >= 246VAC on 230V system for > 3 minutes). | Calibrate AC line voltage and check incoming power source. | DIY Safe |
N/A | "LO" then "FC" / "HI" then "FC" (Frequency shutdown) Possible Cause: Incoming generator frequency is outside acceptable operating limits (< 57 Hz or > 63 Hz). | Adjust generator output frequency to 60 Hz with unit operating in COOL mode. | DIY Safe |
N/A | "HI" then "PS" (High pressure shutdown, compressor running) Possible Cause: Head pressure above 425 psi during cooling operation due to restricted airflow or condenser fan failure. | Check if condenser fan is operating properly and ensure condenser coil is clean. | DIY Safe |
N/A | "HI" then "—" (High pressure shutdown, compressor off) Possible Cause: High pressure switch or wiring has failed open during cooling operation. | Replace high pressure switch or check high pressure switch wiring for an open circuit. | DIY Safe |
N/A | "IS" then "—" / "CS" then "—" / "ES" then "—" Possible Cause: Internal temperature sensor error, compressor discharge temperature sensor failure, or evaporator temperature sensor failure/short. | Replace faulty sensor and associated cabling. | DIY Safe |
N/A | "LO" then "ES" (Evaporator sensor shutdown) Possible Cause: Evaporator icing in COOL mode (evaporator sensor temperature < 34°F). | De-ice the evaporator by running the internal fan only in manual mode. | DIY Safe |
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.