Furnace does not ignite, burner never lights, display shows E01 shortly after a call for heat.

Safety first: Turn off the main gas supply and isolate electrical power to the Cointra furnace before removing any covers. Wait for all hot surfaces to cool.

Step-by-step checks:

• Reset the unit: Turn the furnace OFF at the main switch for 30 seconds, then turn it back ON and request heat. If E01 returns, continue.
• Inspect the flame sensor: Locate the flame sensor (usually a small rod near the burner). Remove it and gently clean the metal rod with fine emery cloth or a non-abrasive scouring pad to remove oxidation. Reinstall and ensure the wiring connector is tight.
• Check the ignition electrode: Inspect the ignition electrode for cracks, carbon buildup, or damage. Clean the tip with fine sandpaper and verify the spark gap and position per the Cointra service manual (electrode tip must be in the gas stream).
• Verify gas supply: Make sure the gas shutoff valve to the furnace is fully open. If other gas appliances are weak or not working, contact your gas supplier to check pressure.
• Check gas valve operation: With power restored and a call for heat, listen for the gas valve click. If there is no click and 230 V (or rated voltage) is present at the valve terminals, the valve may be faulty and should be replaced by a qualified technician.
• Bleed air from line (if recently installed): If the furnace is new or gas supply was interrupted, there may be air in the line. A licensed technician should purge the gas line and verify inlet pressure with a manometer.

When to call a professional: If cleaning the flame sensor and electrode does not resolve E01, or if you suspect gas pressure or valve issues, contact an authorized Cointra service center. Do not attempt to disassemble the gas valve or burner assembly beyond basic access.