Daikin A5 Error Code: Causes, Fixes, and How to Solve It

The A5 error code indicates a coil temperature protection issue.

This happens when the indoor unit detects that the heat exchanger is:

• too cold (freezing)
• or too hot (overheating)

In most cases, A5 is caused by airflow problems or restricted circulation

If you’re not sure what the A5 error means in the bigger picture, you can check the full breakdown of all Daikin codes in our complete guide on Daikin Error Codes. It explains how different error groups work and helps you quickly identify whether your issue is electrical, refrigerant-related, or system-wide.

What causes Daikin A5 error

Dirty air filter (most common)

• Blocks airflow
• Causes coil freezing

Blocked airflow

• Closed vents
• Furniture blocking unit
• Dust buildup

Frozen evaporator coil

• Ice buildup inside unit
• Stops normal operation

Low refrigerant

• Reduces pressure
• Causes freezing

Fan issues

• Weak airflow
• Motor problems

Symptoms of A5 error

• Weak or no cooling
• Ice on indoor unit
• AC runs but not effective
• System shuts down intermittent

A5 is often visible before failure (unlike A0).

How to fix Daikin A5 error

Step 1: Turn off the system

Let the unit rest and defrost if needed.

Step 2: Check and clean air filter

• Remove filter
• Wash or replace

This fixes a large % of A5 cases.

Step 3: Allow ice to melt

If frozen:

• turn off AC
• wait 2 to 6 hours

Step 4: Check airflow

• Open vents
• Remove obstructions
• Clean intake area

Step 5: Restart system

If issue is airflow-related, error should disappear

When A5 is not a DIY fix

Call a technician if:

• Error returns after cleaning
• Ice keeps forming
• System has low cooling
• You suspect refrigerant issue

Repair cost for A5 error

Problem	Cost
Filter replacement	$0–$50
Coil cleaning	$100–$300
Refrigerant repair	$300–$900
Fan motor repair	$300–$700

Is A5 error serious

Usually no, but:

If ignored:

• can damage compressor
• can lead to expensive repairs