FieldBench
Daikin codes

Daikin

Hum / no start

Lockout

Cap / start

Compressor hums, outdoor fan may run.

Walk Hum / no start in Diagnose

2 plates — walk the one on the cabinet

First check

1 Is Y actually at the contactor?

On Daikin DC5SE a silent outdoor is often no Y. Measure 24 VAC coil-to-C at the contactor on a cool call. Dual cap (fan and herm). Replace on values, not just a bulge.

Expect: ~24 VAC at the coil when the indoor is calling.

If fail: Indoor Y / IFC / stat — not a capacitor.

The rest of the walkthrough is Diagnose.

On the plates

  • Dual cap (fan and herm). Replace on values, not just a bulge.
  • Hard-start only after the cap and windings are proven.

Plates that use Hum / no start

Same number, other makers

Hum / no start on Daikin is not the same code on these plates.