What it means
Daikin's US service manual calls it freeze-up protection control or heating peak-cut control, and says it trips in cooling when the indoor coil is below 0°C (32°F), and in heating when it is above 60 to 62°C (140 to 144°F). Daikin's global code list words it as high pressure control in heating, freeze-up protection control in cooling.
What to check, in order
- Clean the air filters
Daikin lists a clogged air filter as a cause and recommends cleaning the filters about every two weeks. Wash them with water or vacuum them, and let them dry in the shade before refitting.
- Clear the air path
Make sure nothing is blocking the air inlet or outlet of the indoor unit, such as curtains or furniture. Daikin lists air short-circuiting back into the unit as a cause.
- Restart with the remote
Daikin's troubleshooting page says to restart from the remote once the filters are clean and nothing is in the way.
When to call an engineer
If it keeps happening with clean filters, Daikin's service manual says the next checks are dust built up on the indoor coil, a faulty indoor coil thermistor and the indoor control board. Coil cleaning and parts are a job for an air conditioning engineer or HVAC technician.
Quick answers
What does the Daikin A5 error code mean?
In cooling, the indoor coil has got so cold it could ice up, so the unit has stopped to protect itself. In heating, the indoor coil has got too hot, so the unit has cut back or stopped to keep the pressure down. Daikin's US service manual calls it freeze-up protection control or heating peak-cut control, and says it trips in cooling when the indoor coil is below 0°C (32°F), and in heating when it is above 60 to 62°C (140 to 144°F). Daikin's global code list words it as high pressure control in heating, freeze-up protection control in cooling.
Can I fix Daikin A5 myself?
Very easy (about 20 minutes, plus drying time). Start with: clean the air filters; clear the air path; restart with the remote. If it keeps happening with clean filters, Daikin's service manual says the next checks are dust built up on the indoor coil, a faulty indoor coil thermistor and the indoor control board. Coil cleaning and parts are a job for an air conditioning engineer or HVAC technician.
Is Daikin A5 worth repairing?
Usually free. Usually a dirty filter or blocked airflow. Cleaning the filters is the first fix Daikin lists.
Checked against
- Daikin Service Manual SiUS042113E, FTXM-V / RXM-V inverter pair wall mounted type (manualslib copy of the Daikin PDF)
- Daikin: Simple Self-Diagnosis by Malfunction Code, SM-TS3, list of error codes (PDF)
- Daikin One error code table for ductless (S21) units, daikinac.com (PDF)
- Daikin Global: Troubleshooting, split and multi-split air conditioners
- Daikin CTXA / FTXA User reference guide 4PEN518786-10V, English (PDF)
Last reviewed October 2026. Manufacturers update their pages, and your manual is the final word. Spotted a mistake? Email contact@appliance-error-codes.com.