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Fujitsu Air Conditioner 71-74 Error Code

Outdoor unit temperature sensor error. Here is what it means and how to clear it, easiest fix first.

71-74
May need a pro

One of the outdoor unit's temperature sensors is reading open, shorted or out of range: 71 is the discharge pipe sensor, 72 the compressor sensor, 73 the outdoor coil sensor and 74 the outdoor air sensor. The sensor, its connector or the outdoor board can 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 7 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. The pattern above is for 71; for 72, 73 and 74 the Timer lamp flashes 2, 3 or 4 times instead. Some models also use 77 for the heat sink sensor. 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.

Safety first: unplug the air conditioner (or switch off its breaker) before touching filters, hoses or panels. If you smell burning or gas, or see water near the outlet, stop and call a professional.

How to fix Fujitsu 71-74

  1. 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.

  2. 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 sensor named by the code and replace it or the outdoor board.

Parts that commonly cause 71-74

Order parts by your exact model number so they fit.

Other Fujitsu air conditioner codes

Frequently asked questions

What does 71-74 mean on a Fujitsu air conditioner?

One of the outdoor unit's temperature sensors is reading open, shorted or out of range: 71 is the discharge pipe sensor, 72 the compressor sensor, 73 the outdoor coil sensor and 74 the outdoor air sensor. The sensor, its connector or the outdoor board can be at fault.

Can I fix Fujitsu 71-74 myself?

Only the basic checks. You can safely try the steps above, but 71-74 usually points to a part or fault that needs a technician.

What if 71-74 keeps coming back?

A code that returns after a reset and the checks above usually means a part is wearing out. Note when 71-74 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.

References