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Fujitsu Air Conditioner 41 Error Code
Room temperature sensor error. Here is what it means and how to clear it, easiest fix first.
The sensor that measures the room air at the indoor unit is reading open, shorted or out of range. The sensor, its connector or the indoor board may be at fault.
Lamp pattern: on models that show faults with the indicator lamps, Fujitsu's tables for many current wall-mounted (RL/RLS/RLX, LZAH), compact ducted (RGLX) and RLF multi-zone units show this code as the Operation lamp flashing 4 times and the Timer lamp flashing 1 time, with the Economy lamp marked "continuous". Other Fujitsu units, such as universal-mount and ceiling-suspended models, use different lamps. A wired controller shows the code as a number. Listed as 41.1 in Fujitsu's FGLair app table. On the older code set this fault used 02 or 03. Fujitsu's older code set (for example older 9CQ/9RLQ/12CQ wall units, RMLQ-series multi-zone heads and some RCLX ceiling cassettes) uses different numbers for many faults, so always check the manual for your model.
How to fix Fujitsu 41
Reset the power at the breaker
Switch the system off with the remote, then turn off its circuit breaker in your home's main panel. Wait about 5 minutes, switch the breaker back on and restart the unit. If the code returns within a few minutes, write it down for the technician.
Record the details for the technician
Write down the exact code, the model numbers from the labels on the indoor and outdoor units, and what the system was doing when the code appeared. Leave the unit switched off if the code keeps returning, so a fault doesn't cause further damage.
When to call a technician
A technician needs to test the room thermistor's resistance and replace it or the board.
Parts that commonly cause 41
- room temperature thermistor
- indoor control board
Order parts by your exact model number so they fit.
Other Fujitsu air conditioner codes
- 11Indoor and outdoor units can't communicate
- 12Wired remote controller communication error
- 18External or Wi-Fi adapter communication error
- 32Indoor unit control board error
- 35MANUAL AUTO button stuck
- 42Indoor coil temperature sensor error
- 51Indoor fan motor error
- 53Drain pump error
- 62Outdoor unit main board error
- 63Inverter error
- 65IPM (power module) protection
- 71-74Outdoor unit temperature sensor error
- 94Compressor overcurrent (trip detection)
- 95Compressor motor control error
- 97Outdoor fan motor error
- 99Reversing (4-way) valve error
- A1Discharge temperature too high
- A3Compressor temperature too high
- A5Low pressure error
Frequently asked questions
What does 41 mean on a Fujitsu air conditioner?
The sensor that measures the room air at the indoor unit is reading open, shorted or out of range. The sensor, its connector or the indoor board may be at fault.
Can I fix Fujitsu 41 myself?
Only the basic checks. You can safely try the steps above, but 41 usually points to a part or fault that needs a technician.
What if 41 keeps coming back?
A code that returns after a reset and the checks above usually means a part is wearing out. Note when 41 appears (which cycle, how often) and have your model number ready; it helps a technician bring the right part on the first visit.
Last reviewed 2026-10-19. Codes and steps can vary by model; check your owner's manual.