Heater attempts to start but shuts down with F02; fan may run briefly.

Safety first: Turn off electrical power and shut off the gas supply at the gas cock before servicing. Gas leaks and ignition issues can cause fire or explosion.

• Verify gas supply: Confirm the main gas valve to the Nirvana heater is fully open. Check that other gas appliances in the home are working normally to rule out a supply issue.
• Inspect burner compartment: Remove the front panel and burner access cover. Look for signs of soot, rust flakes, or debris around the burners and igniter.
• Check igniter: Locate the Nirvana hot surface igniter / spark igniter. Inspect for cracks, heavy oxidation, or damage. Ensure the igniter tip is positioned correctly over the burner as per the service manual (gap and angle).
• Clean flame sensor: Many Nirvana models use a combined igniter/flame rod or a separate flame sensor rod. Gently clean the rod with fine steel wool or emery cloth to remove oxidation. Do not sand aggressively.
• Check gas pressure (pro only): A licensed gas technician should verify inlet and manifold gas pressure at the Nirvana gas valve using a manometer.
• Reassemble and test: Restore gas and power, then call for heat. If F02 returns after cleaning and confirming gas supply, the igniter or gas valve may need replacement by a professional.