Furnace displays Er8 and shuts down; no ignition or incomplete startup.

Safety first: Turn off and unplug the furnace. Allow it to cool completely before working near the burn pot or igniter.

Steps:

• 1. Verify fuel quality: Ensure pellets or coal are dry and within US Stove specifications. Wet or poor-quality fuel can prevent ignition.
• 2. Clean the burn pot: Remove the burn pot and scrape out clinkers and ash. Make sure all air holes are open. A blocked burn pot can prevent the igniter from lighting the fuel.
• 3. Locate the igniter: Typically mounted under or behind the burn pot in a tube or bracket, with high-temperature wires leading to the control board.
• 4. Inspect wiring and connections: Check for burnt, brittle, or loose wires at the igniter and control board. Repair or replace damaged wiring with high-temperature-rated wire.
• 5. Test the igniter: With power disconnected, remove the igniter and check its resistance with a meter. Compare to the specification in your manual. An open circuit usually indicates a failed igniter.
• 6. Replace the igniter if defective: Install the correct US Stove igniter element, ensuring it is properly positioned in the igniter tube and not touching metal surfaces.
• 7. Restart and observe: Restore power, start the furnace, and watch the ignition sequence. You should see the igniter glow and fuel ignite within the specified time. If Er8 persists, the control board or timing may require professional diagnosis.