What F5 Means
The WO-series technical service guide lists F5 as “element supervisor disabled (upper oven)”. Where F1 says the supervisor caught a relay misbehaving, F5 says the board could not keep its element monitoring running for the upper oven. On double ovens the lower-oven version of this error is reported as Fr.
Common Causes of F5
- Temperature control board supervisor circuit failed
- Relay feedback wiring disconnected
- Supply voltage problem at the oven’s terminal block
🔧 One Safe Check You Can Try
Cancel the oven. Try one power reset at the breaker only when the oven is cool. If F5 returns, leave the upper oven unused; the board is telling you it can no longer police its own heating circuit.
⚠ Why You Shouldn't Go Further Than That
- The terminal block and relay board are on the full 240-volt feed; checking supply voltage under load is an electrician-grade test.
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.