If the indoor fan runs, does that mean the compressor is faulty?

No. The indoor fan can run while the outdoor side fails to start. The control path should be checked before the compressor is blamed.

Can a contactor relay fault stop cooling completely?

Yes. If the contactor relay does not switch correctly, the outdoor side may not start, so cooling will not begin even though the indoor unit appears active.

What should I send for a quick second opinion?

Tell us whether the outdoor side is silent or starts and stops. A short video helps us narrow the likely fault path faster.

Outdoor Unit Not Running, Contactor Relay Fault

Indoor airflow was running, but cooling never started because the outdoor side did not run. The first advice jumped to major replacement, but the fault path was smaller and easier to prove.

Case Details

LocationPunggol, Singapore

BrandDaikin

Unit age9 yrs

ComplaintThe fan was blowing, but the room stayed warm and the outdoor side sounded completely silent. A large repair was suggested after a short check.

CauseContactor relay fault in the outdoor control path

The Assessment

When the outdoor side does not start, we check the start path first. We do not jump to the largest part failure from the symptom alone.

Indoor side was running but cooling did not begin
Outdoor start sequence did not complete
Contactor relay response did not match normal operation
The fault path did not support immediate compressor replacement

The Diagnosis

The problem was in the outdoor control path. The contactor relay was not switching correctly, so the outdoor side did not start. The indoor fan still ran, which made the symptom look more confusing than it was.

Correct the contactor relay fault, then retest the full start sequence and confirm stable cooling before discussing any larger repair scope.

The Outcome

After the contactor relay issue was corrected, the outdoor side started normally and cooling returned. The client did not need the larger replacement first suggested.

Timeline

Initial complaintIndoor side ran but no cooling started

First adviceMajor replacement was suggested

Snowflake visitContactor relay fault path confirmed

After correctionOutdoor side started and cooling returned

What This Means for You

This pattern often gets overdiagnosed because the indoor side still appears to be working.

Indoor fan runs but the room does not cool
Outdoor side stays quiet during a cooling call
Major replacement was suggested before the start path was explained

Ask for the outdoor start path to be checked first. It can save you from paying for the wrong repair.