Alliance error code F0
What it means
Low refrigerant protection.
Possible causes
Undercharged system after leak or incorrect charging Expansion valve malfunction causing low evaporator pressure Chronic small leaks
Suggested fix
Evaluate suction pressure and superheat and inspect for leak indicators; repair leaks and charge precisely by weight using appropriate recovery and charging equipment before resetting the fault.
Safety first. Isolate the power supply before inspecting any unit. Refrigerant-circuit
and electrical repairs must be carried out by a qualified, registered technician.
Other Alliance codes
- E0 — Meaning depends on unit type — Inverter midwall: EEPROM error; Inverter under-ceiling/cassette/ducted: communication between indoor and outdoor units; Package unit: phase rotation / phase missing; Integrated water heater: error of sensor T5U.
- E1 — Meaning depends on unit type — Vertu fixed-speed midwall / Fixed-speed under-ceiling/cassette/ducted: EEPROM error; Atlantic midwall: outdoor tube sensor fault; Inverter midwall: indoor-outdoor communication error; Inverter under-ceiling/cassette/ducted / Pool heater / Commercial water heater: phase rotation / phase missing; Package unit: outdoor coil sensor, system A; Portable: room temperature sensor error; Water heater (retrofit): phase reversal / phase missing error; Integrated water heater: error of sensor T5L.
- E2 — Meaning depends on unit type — Vertu fixed-speed midwall / Inverter midwall / Fixed-speed under-ceiling/cassette/ducted: zero-crossing detection error; Atlantic midwall: room temperature sensor open or short circuit; Inverter under-ceiling/cassette/ducted: communication error between indoor unit and master unit; MAC cassette: room temperature sensor failure; Package unit: outdoor coil sensor, system B; Portable: evaporator temperature sensor error; Water heater (retrofit): communication error between unit and wired control, or sensor damaged; Pool heater: outdoor unit and wire controller communication error; Integrated water heater: tank and wired controller communication error; Commercial water heater: communication failure between wired remote and main unit.
- E3 — Meaning depends on unit type — Vertu fixed-speed midwall / Inverter midwall / Fixed-speed under-ceiling/cassette/ducted: indoor fan error; Atlantic midwall: indoor coil sensor open or short circuit; MAC cassette: coil temperature sensor failure; Portable: condenser temperature sensor error; Water heater (retrofit) / Pool heater: outlet water temperature sensor error; Commercial water heater: outlet water temperature sensor failure.
- E4 — Meaning depends on unit type — Inverter midwall: indoor room temperature sensor open or short circuit; Inverter under-ceiling/cassette/ducted: outdoor temperature sensor error; MAC cassette: condenser sensor failure; Water heater (retrofit): water temperature sensor failure in the water tank; Pool heater: inlet water temperature sensor error; Integrated water heater: condenser pipe temperature sensor error; Commercial water heater: water temperature sensor in the water tank failure.
- E5 — Meaning depends on unit type — Vertu fixed-speed midwall / Fixed-speed under-ceiling/cassette/ducted: room temperature sensor open or short circuit; Atlantic midwall: indoor fan fault; Inverter midwall: indoor coil sensor open or short circuit; Inverter under-ceiling/cassette/ducted: compressor discharge temperature sensor error; MAC cassette: water pump temperature sensor error; Package unit: indoor coil sensor, system A; Water heater (retrofit): condenser temperature sensor error; Pool heater: evaporator pipe temperature sensor error; Integrated water heater: outdoor ambient temperature sensor error; Commercial water heater: condenser temperature sensor failure.
- E6 — Meaning depends on unit type — Vertu fixed-speed midwall / Fixed-speed under-ceiling/cassette/ducted: indoor coil sensor open or short circuit; Atlantic midwall: EEPROM error; MAC cassette: outdoor malfunction; Package unit: indoor coil sensor, system B; Water heater (retrofit): outdoor ambient temperature sensor error; Integrated water heater: sensor Tp error; Commercial water heater: outdoor ambient temperature sensor failure.
- E7 — Meaning depends on unit type — Atlantic midwall: external feedback fault (check interconnecting wiring); MAC cassette: EEPROM malfunction; Water heater (retrofit): sensor failure at water pump outlet; Pool heater: ambient temperature sensor error; Commercial water heater: electric heating pipe temperature sensor failure.
- E8 — Meaning depends on unit type — Atlantic midwall: overheat detection / defrosting; Inverter under-ceiling/cassette/ducted: outdoor unit address error; MAC cassette: water-level alarm; Integrated water heater: electric leakage protection.
- E9 — Meaning depends on unit type — Inverter under-ceiling/cassette/ducted: power voltage error; Package unit: indoor temperature sensor error; Water heater (retrofit): T8 temperature sensor error; Pool heater: water flow switch error.