E13 displayed, unit may lock out; often associated with flue or combustion issues.

Danger: Flue gas issues can lead to carbon monoxide hazards. If you smell exhaust or feel unwell, evacuate and call emergency services.

• 1. Inspect exhaust vent: From outside, check that the flue termination is not blocked by snow, ice, or debris. Clear any obstructions.
• 2. Check vent materials and joints: Ensure that only approved vent materials are used and that all joints are properly sealed and supported. Look for signs of overheating or discoloration.
• 3. Locate flue sensor: The flue gas temperature sensor is typically mounted in the exhaust outlet near the heat exchanger. Inspect its wiring and connector.
• 4. Sensor check: With power off, remove the sensor and inspect for soot or corrosion. Clean gently if dirty. If you have a meter, check resistance and compare to the manufacturer’s chart.
• 5. Reset and monitor: Reinstall the sensor, restore power, and reset the error. Monitor operation. If E13 recurs quickly, do not continue to run the unit.
• 6. Professional combustion analysis: A qualified Triangle Tube technician should perform a combustion analysis, verify gas input, and replace the flue sensor or gas valve if necessary.