If your Daikin VRV system is showing error code A6, an indoor unit fan motor is not doing what the system asked.
The useful thing about this code is that it covers six distinct conditions, and they range from an expensive component failure down to a blocked filter.
What A6 actually covers
| Condition | What it means |
|---|---|
| Fan motor lock | The motor is physically prevented from turning |
| Fan motor abnormality | The motor is faulty or not responding as commanded |
| Overload / overcurrent / lock | Drawing current beyond its limit |
| Blower motor not running | Not turning at all |
| Fan motor status abnormality | Feedback does not match what the system expects |
| Low indoor airflow | Airflow below expected — often a restriction, not a motor fault |
That last row is the one worth noticing. A6 does not necessarily mean a failed motor. Low indoor airflow is a condition the code reports, and the cause is frequently a blocked filter, a restricted duct or a blocked grille.
Establishing which condition you have is the difference between a filter change and a motor replacement.
One thing worth correcting
A6 is sometimes described in code lists as a low pressure fault. It is not.
On Daikin VRV, low pressure protection is E4 and refrigerant shortage is U0. A6 is an indoor fan motor code, full stop.
The distinction matters practically: a technician who treats an A6 as a refrigerant problem will be putting gauges on a system whose actual fault is a blocked filter in a ceiling cassette.
How urgent is it?
Moderately urgent. The affected zone has stopped conditioning, which generates complaints, but nothing is being damaged rapidly and there is no safety issue.
There is a slower cost worth knowing about. If the cause is a restriction rather than a failed motor, the fan has been working against that restriction continuously — which shortens motor life and changes how the coil behaves, occasionally contributing to drain problems.
What it typically costs
Low to medium, with the cheap outcomes genuinely common.
If the cause is a filter, an obstruction or a closed grille, the fix may be minimal. A replacement indoor fan motor is a modest component.
The main cost variable, as with most indoor unit work, is access — reaching a ceiling-mounted cassette in occupied tenant space, which may need coordination or out-of-hours attendance.
What causes it
- Blocked or heavily loaded filter — the cheapest and one of the most common
- Restricted or damaged ductwork reducing airflow
- Blocked supply or return grilles — sometimes furniture or tenant storage
- Bearing wear in the fan motor
- Motor failure from age or from running against a restriction
- Obstruction in the fan assembly — debris or a dislodged component
- Control or feedback fault where the motor runs but is not reporting correctly
What happens if you leave it
The zone stays down, so somebody will chase it.
The less obvious cost is the recurrence pattern. If a motor failed because it spent years fighting a restriction and only the motor gets replaced, the new one inherits the same conditions. Repeat A6 on the same unit almost always means the underlying restriction was never found.
What we check
- Establish which condition the code is reporting — motor fault or airflow restriction.
- Inspect the filter first, since it is the most common and cheapest cause.
- Check grilles and the airflow path for obstruction, including anything tenants have placed.
- Test motor operation and current draw against specification.
- Check the fan assembly for free rotation, bearing wear and obstruction.
- Verify the feedback circuit — occasionally the motor runs correctly and only the reporting is wrong.
- Inspect adjacent ductwork for damage or restriction where accessible.
What you can tell us before we arrive
- Which zone? Speeds up access arrangements considerably.
- Is the fan audibly running? Distinguishes a stopped motor from an airflow problem immediately.
- When were filters last changed? Frequently the answer.
- Has this unit done this before? Recurrence points at an unaddressed restriction.
- Has anything been placed near the grilles? Tenant storage is a recurring cause.
Related codes
- A3 — Drain level control fault. Another indoor unit fault; airflow changes can affect coil behaviour and drainage.
- J3 / J5 — Thermistor faults. Other indoor-side sensing worth checking if both appear.
- U4 — Communication error. If the affected unit has also dropped off the control wiring.
Check the cheap causes first
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Related codes
Error A3 is a drain level control fault. The system stopped an indoor unit to prevent condensate overflowing into the ceiling below — which is the real risk.
The J-series codes are thermistor faults. The sensors themselves cost very little — reaching them on a large commercial VRV unit is where the money goes.
Error U4 means your indoor and outdoor units stopped communicating. The most frequently seen Daikin VRV fault, and usually one of the cheaper ones to put right.
Frequently asked questions
What does error code A6 mean on a Daikin VRV system?
An indoor unit fan motor fault. The code covers several distinct conditions including a locked motor, an overload or overcurrent, a motor not running at all, a status feedback mismatch, and simply low indoor airflow. They have quite different repairs.
Does A6 always mean the fan motor has failed?
No, and that matters for cost. One of the conditions this code covers is low indoor airflow, which is often a blocked filter, a restricted duct or a closed grille rather than anything wrong with the motor itself. That is a much cheaper outcome.
Is A6 a low pressure fault?
No. A6 is an indoor fan motor code. Low pressure protection on Daikin VRV is E4, and refrigerant shortage is U0. The two get conflated in some code lists, which sends technicians looking at refrigerant when the fault is airflow.
Can a dirty filter cause an A6 error?
It can contribute. Restricted airflow is one of the conditions the code covers, and a heavily blocked filter reduces flow enough to trigger it. It also makes the motor work harder continuously, which shortens its life if left in place.
How much does an A6 error cost to fix?
Usually low to medium. If the cause is a filter, restriction or obstruction it may be minimal. A replacement fan motor is a modest part, and the main cost is access to a ceiling-mounted indoor unit in occupied tenant space.
Why does A6 keep coming back on the same unit?
Recurring A6 on one unit usually means the underlying restriction was never addressed. Replacing a motor that failed because it was fighting a blocked filter or duct puts a new motor into exactly the same conditions. Finding the restriction is what stops it recurring.