What F3 Means
F3 means the oven's temperature sensor (RTD) circuit is reading open or shorted, so the control board can no longer trust what temperature the cavity is actually at — the oven typically shuts off heating and displays the code rather than risk overheating.
Common Causes of F3
- Failed or drifting temperature sensor (RTD probe)
- Damaged or loose sensor wiring harness
- Control board failing to read the sensor correctly
🔧 One Safe Check You Can Try
Power-cycle the oven at the breaker for a couple of minutes; if F3 returns immediately on the next bake attempt, the sensor circuit problem is confirmed rather than a one-time glitch.
⚠ Why You Shouldn't Go Further Than That
- The sensor probe sits inside the hot cavity near the rear wall, wired directly into the control board — testing it live risks both a shock and a burn.
- Swapping the sensor without confirming the wiring harness is intact can leave the exact same code showing after the part is replaced.
- Oven sensor and heating-element wiring share routing behind the rear panel; disturbing the wrong wire can introduce a second, unrelated problem.
- Panel removal to reach the sensor typically involves disassembly that can affect the unit's remaining parts warranty — check your terms first.
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.
Technical Reference
- Code
- F3
- Appliance
- Monogram wall oven
- Maker documentation
- Monogram owner manuals and use & care guides
- Checked
- September 2026
Code meanings can change between control generations. Before acting on a code, match the full model number on your appliance's rating label against the manual for that model. We are an independent repair service, not affiliated with Haier US Appliance Solutions, Inc.