Monogram Ovens F3 Error: Open sensor circuit
The F3 error on a Monogram wall oven indicates the oven temperature sensor circuit is open. The sensor or its wiring has a complete break in the circuit, so no resistance reading reaches the control board and the oven cannot regulate temperature.
~20%
DIY Fixable
From $200
Typical Repair Cost
1–3 hrs
Pro Repair Time
Quick Assessment
Answer to continue safely
Is it safe to keep using?
No. The wall oven cannot heat with F3 active. The control will not energize any heating element without a valid sensor reading. The oven must remain out of service until the open circuit is repaired.
Can I reset the code?
No. A power reset will not resolve F3 if the sensor or harness is physically broken. The open circuit must be repaired — by replacing the sensor or harness — before the oven will operate.
When to stop immediately?
Stop if you notice: The sensor wiring shows visible heat damage or melted insulation, You smell burning when the oven is powered on.
Symptoms You May Notice
Wall oven produces no heat
The oven fails to begin heating when any cooking function is selected; the heating elements never receive power because the control cannot verify a temperature reading.
Oven temperature display reads dashes
Instead of showing the current cavity temperature, the display shows "---" or blank, indicating the control is receiving no signal from the sensor.
F3 appears immediately on startup
The code displays within seconds of turning on the oven, before any preheat has occurred, because the open circuit is detected instantly.
Self-clean will not start
The self-clean function is blocked because the oven cannot confirm a valid temperature starting point.
Possible Causes
Broken internal element in the RTD sensor
The resistance wire inside the temperature probe has fractured, creating a complete open circuit that the multimeter reads as infinite resistance or OL.
DIY PossibleBroken conductor in the sensor wiring harness
One of the two wires in the harness connecting the sensor to the control board has broken, cutting the circuit path.
DIY PossibleDisconnected sensor harness connector
The sensor harness has pulled out of its connector at the sensor or at the control board, opening the circuit.
DIY PossibleSafe Checks You Can Do
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1
Power Reset
Turn off the wall oven circuit breaker for 60 seconds. Restore power and test whether F3 returns. A true open circuit will cause F3 to return immediately.
Unlike some codes that require time to develop, F3 caused by a broken sensor or wire will appear on the very first startup after reset.
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2
Measure Sensor for Open Circuit
Disconnect the wall oven from power. Access the temperature sensor inside the oven cavity and disconnect the harness plug. Use a multimeter set to ohms to measure across the two sensor terminals. A healthy sensor reads approximately 1,080 ohms. An OL or infinite reading confirms the sensor element has broken and the sensor must be replaced.
On most Monogram wall oven models, the sensor harness plug is accessible from inside the oven cavity without pulling the unit out of the wall.
Tools required -
3
Check Harness Connectors
If the sensor tests at 1,080 ohms, inspect both harness connectors — at the sensor and at the control board — to ensure they are fully seated. On some installations vibration can allow a connector to back out partially. Reseat any loose connectors and test again.
The control board connector is usually accessible from behind the oven or from the oven bottom depending on model — consult the installation guide for your specific Monogram model.
When to Call a Professional
Contact a qualified technician if:
- Sensor tests at 1,080 ohms and all connectors are seated but F3 persists
- The wiring harness break is inside the oven wall cavity and is not accessible without dismantling the oven
- You are not comfortable pulling a wall oven out of its cabinet for repair
Need Professional Help?
Find qualified technicians in your area for proper diagnostics and repair.
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