Wolf GR Oven Will Not Ignite: CFH Sequence

Most Common Reasons a Wolf GR Gas Oven Will Not Ignite

• The convection fan is running during preheat: Air movement can lift the gas flame away from the electrode before the oven completes its ignition check. Wolf specifically directs GR owners to turn the convection fan off during preheat. The homeowner-visible clue is the fan running while Bake or Broil is trying to light. If ignition still fails with the correct fan state, the technician must verify flame establishment and electrode sensing under the exact selected mode.
• Only one oven mode is failing: Bake and Broil use different burner and ignition hardware on models equipped with both modes. Bake working while Broil fails, or the reverse, points to the affected burner, electrode, wire, connection, gas delivery, or matched control output rather than a whole-oven outage. The useful evidence is which mode was selected, whether it clicked, and whether flame ever appeared. Service must reproduce that mode and test its complete ignition sequence before naming a part.
• A shared oven input is preventing both modes from lighting: When neither Bake nor Broil establishes flame, a common electrical input, gas-delivery condition, thermostat or command input, wiring connection, or direct-spark ignition control becomes more relevant. Working surface burners do not clear the oven's separate ignition system. The technician must verify the GR oven command, electrical input, gas delivery, spark, flame sensing, and control response together.
• The oven has locked out after failed ignition attempts: On the current GR sequence, slow-flashing CFH follows two unsuccessful ignition attempts and prevents ordinary continued operation. The visible evidence is the slow flash after the automatic sequence or after the single permitted post-CFH attempt. The lockout reports failed ignition; it does not identify the cause. Service must retrieve the exact sequence and determine why flame did not establish or was not confirmed.

Safety Gate

Stop the oven immediately for gas odor, delayed or forceful ignition, abnormal flame, smoke, arcing, or any sign that flame did not establish cleanly. Those conditions cancel every operating check below. Do not wait through another sequence to collect more evidence.

If CFH slow-flashes after unsuccessful ignition attempts, or the one official post-flash cycle also fails, discontinue use of the failed oven mode. Do not keep alternating Bake and Broil or cycling the control until it lights.

Confirm This Is a GR Gas Oven

Use the model label, not the appearance of the range. This page is for the current GR gas range oven. A Wolf DF range has gas surface burners but an electric oven and belongs to Wolf dual fuel range oven turns on but does not heat. Do not transfer GR purge, CFH, electrode, or DSI logic to a DF electric cavity.

Older R-series or other gas ovens may use different controls and sequences. Apply their exact manual rather than treating current GR timing as universal.

Bake, Broil, or Both?

• Bake fails but Broil works: Preserve Bake as the failed mode; do not assume its electrode, wire, valve, burner, or control is the cause.
• Broil fails but Bake works: Preserve Broil as the failed mode on a model that has it; do not confuse normal cycling after successful ignition with a burner that never lights.
• Bake and Broil both fail: Record both results because a shared oven input becomes more relevant.
• Surface burners still work: Record that fact, but do not treat it as proof that the oven has correct ignition power or gas delivery.

Record which mode was selected, whether CFH appeared or flashed, whether clicking occurred, whether flame established, and whether the surface burners operate. Do not keep a failed mode running simply to complete the comparison.

GR Ignition Sequence

Wolf's current GR support describes a specific sequence:

1) A Bake or Broil burner should ignite within 40 seconds.

2) If the burner does not ignite within seven seconds, the oven automatically purges gas for 40 seconds and attempts to reignite.

3) Do not turn the knob back and forth during that automatic purge and retry. The useful observation is whether flame establishes and whether CFH changes.

4) If CFH flashes because ignition failed, Wolf directs the knob Off and back On, preferably after waiting for the flash. This is one official post-flash cycle, not permission for repeated attempts.

5) Slow-flashing CFH means two unsuccessful ignition attempts and safety lockout. Stop there and preserve the pattern for diagnosis.

If the burner lights promptly and the oven heats but food consistently cooks more on one side, use Wolf GR gas oven cooks unevenly side to side.

What Not to Do

• Do not repeat the knob cycle after the single allowed post-CFH-flash attempt.
• Do not continue after any condition listed in the Safety Gate.
• Do not remove panels, burner covers, electrodes, wires, valves, solenoids, or the DSI control.
• Do not test live voltage, gas pressure, a valve, a thermostat, or control-board output.
• Do not apply generic glow-bar instructions to a current GR without exact platform evidence.
• Do not use DF electric elements or relay logic to diagnose a GR gas cavity.

What Diagnosis Must Confirm

• Model: Photograph the model and serial label so current GR instructions can be matched to the range.
• Failed mode: Record whether Bake, Broil, or both fail and whether the other mode was already known to work during normal cooking.
• CFH behavior: Record when CFH appears, whether it flashes slowly, and what happened during the single permitted attempt.
• Ignition timing: Note the time from the command to clicking, any clean flame establishment, and shutdown.
• Preheat state: Record whether the convection fan was off and whether the surface burners operate.

The technician must reproduce the exact GR sequence and verify the mode command, electrical input, spark and flame establishment, electrode and wire condition, gas delivery, valve or solenoid operation, thermostat input, direct-spark ignition output, and connections before naming a component.

FAQ

Is a single whoosh when the GR oven ignites normal?

Wolf says a whoosh may accompany successful GR burner ignition. A single whoosh can be normal when flame establishes promptly and cleanly. Any other ignition sound belongs under the Safety Gate rather than another comparison attempt.