Control board displays Er6 and furnace will not start or shuts down unexpectedly.

Safety first: Turn off and unplug the furnace before adjusting switches or working near moving parts.

Steps:

• 1. Close all doors: Ensure the hopper lid, firebox door, and any service panels are fully closed and latched.
• 2. Locate the hopper lid switch: On many US Stove furnaces, a small micro-switch is mounted near the hopper lid hinge or latch, actuated when the lid closes.
• 3. Check alignment: Slowly close the lid and watch the switch actuator. It should fully depress the switch lever or plunger. If not, adjust the switch mounting position or the lid striker so the switch is fully engaged.
• 4. Inspect wiring: Look for broken or loose wires at the switch and where they connect to the control board. Repair any damaged wiring with proper connectors and high-temperature-rated wire as needed.
• 5. Test the switch: With power off, disconnect the switch and check continuity while manually pressing the actuator. It should change from open to closed. If it does not, replace the switch.
• 6. Replace the hopper lid switch if faulty: Install the correct US Stove hopper lid safety switch and secure it firmly so vibration does not cause intermittent contact.
• 7. Verify operation: Restore power and start the furnace. Open and close the hopper lid to confirm that Er6 appears only when the lid is open, and clears when closed.