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Fujitsu Air Conditioner A1 Error Code
Discharge temperature too high. Here is what it means and how to clear it, easiest fix first.
The compressor's discharge pipe reached about 230°F (110°C) or more twice within a day, so the unit stopped to protect itself. Low refrigerant or a leak, a service valve that isn't fully open, a stuck expansion valve, a blocked strainer, poor outdoor airflow or a faulty sensor can cause it.
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 10 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. Shown as A1.1 on some ceiling cassette models. A3 is a similar protection based on compressor body temperature. 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 A1
Clean the air filters
Turn the system off and switch off its breaker. Lift the front panel of the indoor unit, slide out the mesh filters, and rinse them under lukewarm water or vacuum them gently. Let them dry fully in the shade before refitting them, then restore power.
Clear around the outdoor unit
With the breaker off, remove leaves, grass clippings, snow or anything stored against the outdoor unit, and keep about 2 ft (60 cm) clear on all sides. Brush loose debris off the outside of the coil fins by hand or with a soft brush; do not use a pressure washer or bend the fins.
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.
When to call a technician
A1 usually points to a refrigerant-side problem. Call a licensed HVAC technician and don't try to add refrigerant or touch the service valves.
Parts that commonly cause A1
- expansion valve
- strainer
- discharge thermistor
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
- 41Room temperature sensor error
- 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
- A3Compressor temperature too high
- A5Low pressure error
Frequently asked questions
What does A1 mean on a Fujitsu air conditioner?
The compressor's discharge pipe reached about 230°F (110°C) or more twice within a day, so the unit stopped to protect itself. Low refrigerant or a leak, a service valve that isn't fully open, a stuck expansion valve, a blocked strainer, poor outdoor airflow or a faulty sensor can cause it.
Can I fix Fujitsu A1 myself?
Only the basic checks. You can safely try the steps above, but A1 usually points to a part or fault that needs a technician.
What if A1 keeps coming back?
A code that returns after a reset and the checks above usually means a part is wearing out. Note when A1 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.