Control display shows Er1 and grill will not start ignition sequence

Safety first: Turn the grill OFF, unplug it from power, and allow it to cool completely before opening any panels.

Steps to check and correct:

• Inspect the RTD probe: Locate the temperature probe inside the cook chamber (usually on the side wall). Check for physical damage, broken sheath, or signs of impact or corrosion.
• Check wiring harness: Follow the probe wires through the rear of the cook chamber to the control area. Ensure the harness is not pinched, melted, or chewed. Repair any obvious damage and secure away from hot surfaces.
• Verify connections: Remove the control panel access cover. Find the RTD/temperature sensor connector on the main control board. Unplug and re-seat the connector several times to clear oxidation. Ensure it is fully latched.
• Resistance test (if you have a meter): With the grill unplugged, disconnect the RTD from the board and measure resistance across the two probe leads. At room temperature (20–25°C / 68–77°F) most RTD probes will read roughly 1000–2000 Ω. An infinite (OL) reading indicates an open probe that must be replaced.
• Power cycle: Plug the grill back in, power ON, and see if the Er1 clears. If the code returns immediately and wiring is intact, the probe is likely defective.

When to stop: If wiring and probe test good but Er1 persists, the fault may be on the control board. At that point, contact Napoleon support or a qualified technician before replacing the board.