Blue Star AC F2 Error: Possible Meanings & Fixes

Meaning depends on your model

Possible meaning 1Indoor coil (evaporator) temperature sensor fault

Needs a technician

The control board is getting a wrong reading, or no reading, from the indoor coil (evaporator) temperature sensor. Usually the sensor, its wire or its plug is loose, damaged or has failed.

Common causes

Loose or rusted sensor plug on the control board
Sensor wire cut, pinched or bitten by rats
Sensor has failed (open or short circuit)
Less often, a fault on the control board

Try this at home first

Tick each step as you go

Switch off at the wall socket or MCB for 5 minutes, then restart
If the code does not come back, no further action is needed
Look for any visible wire damage from outside — do not open covers

When to call a technician

If the code returns after a reset, a technician needs to test and usually replace the sensor. It is a common, low-cost repair.

Possible meaning 2Compressor discharge temperature sensor fault

Needs a technician

The control board is getting a wrong reading, or no reading, from the compressor discharge temperature sensor. Usually the sensor, its wire or its plug is loose, damaged or has failed.

Common causes

Loose or rusted sensor plug on the control board
Sensor wire cut, pinched or bitten by rats
Sensor has failed (open or short circuit)
Less often, a fault on the control board

Try this at home first

Tick each step as you go

Switch off at the wall socket or MCB for 5 minutes, then restart
If the code does not come back, no further action is needed
Look for any visible wire damage from outside — do not open covers

When to call a technician

If the code returns after a reset, a technician needs to test and usually replace the sensor. It is a common, low-cost repair.

Possible meaning 3Outdoor air temperature sensor fault

Needs a technician

The control board is getting a wrong reading, or no reading, from the outdoor air temperature sensor. Usually the sensor, its wire or its plug is loose, damaged or has failed.

Common causes

Loose or rusted sensor plug on the control board
Sensor wire cut, pinched or bitten by rats
Sensor has failed (open or short circuit)
Less often, a fault on the control board

Try this at home first

Tick each step as you go

Switch off at the wall socket or MCB for 5 minutes, then restart
If the code does not come back, no further action is needed
Look for any visible wire damage from outside — do not open covers

When to call a technician

If the code returns after a reset, a technician needs to test and usually replace the sensor. It is a common, low-cost repair.

Safety first

Always switch off at the wall socket or MCB before touching any part. Do not open the outdoor unit, control boards or gas pipes yourself — they carry high voltage and pressure.

Frequently asked questions

What does F2 mean on a Blue Star Air Conditioner?

Different Blue Star models use this code for different faults. The most commonly reported meanings are below. Check the model number on the sticker of your unit and your user manual to know which one applies. Indoor coil (evaporator) temperature sensor fault / Compressor discharge temperature sensor fault / Outdoor air temperature sensor fault.

Can I fix Blue Star Air Conditioner error F2 myself?

You can try a reset first: Switch off at the wall socket or MCB for 5 minutes, then restart. If the code returns, call a technician.

Is it safe to keep using the Air Conditioner with F2?

Avoid repeated restarts; running with this fault can cause more damage.

Blue Star AC F2 error

Meaning depends on your model

Possible meaning 1Indoor coil (evaporator) temperature sensor fault

Common causes

Try this at home first

When to call a technician

Possible meaning 2Compressor discharge temperature sensor fault

Common causes

Try this at home first

When to call a technician

Possible meaning 3Outdoor air temperature sensor fault

Common causes

Try this at home first

When to call a technician

Safety first

Frequently asked questions

Other Blue Star AC codes

Same code on other brands

Sources