DCS Cooktops F3 Error: Flame supervision failure
The dcs cooktops error code f3 indicates Flame supervision failure. This guide covers symptoms, diagnostic steps, and repair options. What F3 Means on a DCS Cooktop The F3 code on DCS CPU-366 and CPU-486 cooktops is a flame supervision failure. The cooktop’s safety system lit the burner but the flame sensor — usually a thermocouple […]
No
DIY Fixable
From $250
Typical Repair Cost
60-120 min
Pro Repair Time
Quick Assessment
Answer to continue safely
Is it safe to keep using?
No. F3 means the cooktop cannot confirm a safe flame. Gas may flow without a confirmed burn. Do not use the affected burner until the thermocouple or gas valve is inspected by a qualified technician.
Can I reset the code?
No. Resetting the control board does not fix the underlying thermocouple or valve fault. The F3 will recur on the next ignition attempt until the hardware is repaired.
When to stop immediately?
Stop if you notice: Any persistent gas odor after the burner shuts down., F3 occurs on multiple burners simultaneously..
Symptoms You May Notice
Burner ignites then shuts off with F3
The burner lights normally and burns for 2–10 seconds, then the gas valve closes and the display shows F3, indicating the flame sensor did not confirm a stable signal.
Gas smell after burner shuts down
Because gas briefly flowed before the valve closed, a faint gas odor may linger near the cooktop after an F3 shutdown.
Burner will not stay lit on second attempt
Retrying to light the affected burner reproduces the same ignite-then-shut-off sequence, confirming the flame sensor is not registering the flame.
Only one burner triggers F3
Other burners operate normally, isolating the fault to the thermocouple or flame probe at the affected burner position.
Possible Causes
Dirty or contaminated thermocouple
Grease or food residue coating the thermocouple tip insulates it from the flame, preventing it from generating enough voltage to hold the gas valve open.
DIY PossibleFailed thermocouple or flame probe
The thermocouple element has degraded and no longer produces sufficient millivoltage even in a full flame, requiring replacement.
Requires ProfessionalFaulty gas valve solenoid
The valve's hold-open solenoid is weak and releases even when the thermocouple signal is normal, causing premature shutoff and triggering F3.
Requires ProfessionalSafe Checks You Can Do
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1
Clean the thermocouple tip
With the cooktop cold and the gas supply off, use a fine-grit emery cloth or steel wool to gently clean the thermocouple tip — the small metal probe positioned in the burner flame path. Remove any grease or oxidation buildup.
Even a thin layer of grease on the thermocouple significantly reduces its voltage output. Cleaning is free and often resolves F3.
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2
Check thermocouple position
Ensure the thermocouple tip is correctly positioned within the burner flame path. It should be located where the inner cone of the flame contacts it directly. A knocked or bent probe may need gentle repositioning.
A thermocouple positioned outside the primary flame cone will not generate adequate voltage to hold the valve open.
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3
Ventilate and reset after any gas smell
If F3 triggered with a gas odor, open windows and ventilate the kitchen for at least 5 minutes before retrying. Turn off the gas supply valve and wait before reattempting ignition.
Never attempt to relight a burner immediately after smelling gas — allow full ventilation first.
When to Call a Professional
Contact a qualified technician if:
- F3 persists after thorough thermocouple cleaning and repositioning.
- Thermocouple measures out of spec on a millivoltmeter.
- Gas valve does not hold open even with a confirmed thermocouple signal.
Need Professional Help?
Find qualified technicians in your area for proper diagnostics and repair.
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