Daikin A5 fault code

What it means

Freeze-up protection (cooling) / high-pressure control (heating)

Daikin lists a clogged indoor filter / air short-circuit, or a faulty indoor coil thermistor. Not on Daikin's list, but the same physics: an indoor fan that never turns at all ices the coil too, and A5 is what you end up reading. If the fan is dead, chase the fan — the code is the consequence.

Safety: Isolate before working near the fan — it can restart without warning.

UK models this code applies to

From the Daikin service literature we hold (Daikin CTXM/FTXM-M operation manual 3PEN393186-10J, malfunction-code table (remote self-diagnosis)) — not a scraped list.

Now the harder half: proving what caused it

A5 names a symptom, not a root cause. In the app, the same code opens a guided investigation: what to measure first, the expected values for your exact model, and an honest verdict — including “nothing in this machine is broken” when that's what the readings say.