Boiler display shows 'Outdoor Sensor Fault', 'OD Sensor Open/Short', or outdoor temperature reads extremely high/low.

Safety first: Turn off power before working on control wiring.

• 1. Inspect sensor location: Find the outdoor sensor on the north or northwest exterior wall. Ensure it is not directly in sun or near exhaust vents.
• 2. Check wiring: Follow the two-conductor cable from the sensor back to the Weil-McLain boiler control. Look for cuts, staples through the wire, or loose terminal screws. Tighten and repair as needed.
• 3. Dry out connections: If the sensor or junction box is wet, dry it and reseal with appropriate weatherproofing.
• 4. Replace sensor if needed: If wiring is intact but the control still reports a fault, replace with the correct Weil-McLain outdoor sensor kit.