TOSOT F2 error code

What it means

F2 is part of TOSOT Direct's temperature sensor malfunction group. It means the unit is seeing an invalid temperature input and may shut down to protect itself.

Urgency

Likely causes

1. Faulty pipe or coil temperature sensor
2. Disconnected sensor plug
3. Open or shorted sensor wiring
4. Indoor control board sensor input fault

Homeowner fix

Turn the system off for 10 minutes, then restart once. Do not remove panels or replace the sensor yourself.

When to call a pro

Call a licensed HVAC technician if F2 returns after one reset or the indoor unit cycles incorrectly.

Repair vs replace

Sensor repairs are normally repair-first items. Consider replacement only if an older unit also needs a board or refrigerant-circuit repair.

• TOSOT Multi Ultra Heat 2-Zone 18,000 BTU R-32 208/230V (TMH18D32MO)

  Multi Ultra Heat

• TOSOT Multi Ultra Heat 3-Zone 24,000 BTU R-32 208/230V (TMH24D32MO)

  Multi Ultra Heat

• TOSOT Multi Ultra Heat 4-Zone 28,400 BTU R-32 208/230V (TMH30D32MO)

  Multi Ultra Heat

• TOSOT Multi Ultra Heat 4-Zone 36,000 BTU R-32 208/230V (TMH36D32MO)

  Multi Ultra Heat

For your technician

Technician note: verify the model-specific F2 sensor, check harness and connector, compare resistance with actual coil temperature, and confirm PCB input response. Page context: TOSOT maps this display to the Multi Ultra Heat line; source: TOSOT Direct Mini Split AC Error Codes guide; TOSOT Direct FAQ Split Air Conditioner error code list; TOSOT official Multi Ultra Heat product page; display convention: match the letter F and two marker exactly before comparing neighboring codes.

Which systems show it

Multi Ultra Heat

Sold under more than one brand

Also sold as Cosmo. TOSOT and Cosmo document this code from the same manufacturer source, so F2 means the same thing on either badge and the steps above apply.

Related troubleshooting

Use the symptom guide alongside the exact display code if the unit is flashing, cycling, or showing comfort symptoms.

Related codes

Source

Next step