What F03 Means
F03 indicates a heater relay fault — the control board's switch for turning the heating circuit on and off has failed, which can leave the dryer tumbling with no heat, or in rarer cases, unable to shut heat off.
Common Causes of F03
- Failed heater relay on the control board
- Corroded relay contacts from age and heat cycling
- Wiring fault between the relay and heating element
🔧 One Safe Check You Can Try
Try a full power reset by unplugging the dryer for two minutes — if F03 returns immediately on the next cycle, the relay fault is confirmed rather than a temporary glitch.
⚠ Why You Shouldn't Go Further Than That
- A stuck-on heater relay is a rare but real safety concern, and continuing to run the dryer without confirming which failure mode occurred isn't worth the risk.
- Confirming whether it's the relay itself, corroded contacts, or a wiring fault requires testing the heating circuit directly.
- The heater relay sits on the control board alongside other electronics, and working around it without disconnecting power first is a shock risk.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.