Slant/Fin Error Alert 248 / Alert 233 / Hold 96: Outdoor temperature invalid / outdoor sensor fault
The CH outdoor temperature was invalid (Alert 248; Alert 233 is the Lead-Lag equivalent; Hold 96 = outdoor sensor fault). The CHS ships with Outdoor Reset enabled, so a missing or faulty outdoor sensor triggers this. Documented causes: outdoor sensor not connected, sensor wiring not landed on the OUTDOOR and COM inputs, or a faulty sensor (must be free of ice/snow; check resistance vs Table 15-2). We diagnose and repair it across Greater Vancouver — same-day and after-hours.
The CH outdoor temperature was invalid (Alert 248; Alert 233 is the Lead-Lag equivalent; Hold 96 = outdoor sensor fault). The CHS ships with Outdoor Reset enabled, so a missing or faulty outdoor sensor triggers this. Documented causes: outdoor sensor not connected, sensor wiring not landed on the OUTDOOR and COM inputs, or a faulty sensor (must be free of ice/snow; check resistance vs Table 15-2).
Slant/Fin fault codes can vary by model and series. Use this as a guide — the same code can have more than one cause. Our Technical Safety BC–licensed technicians read the code, confirm it against your unit's manual, and diagnose the true cause before any repair.
Likely causes of Slant/Fin error Alert 248 / Alert 233 / Hold 96
- Outdoor reset sensor not installed while outdoor reset is enabled
- Outdoor sensor wiring not connected to OUTDOOR and COM inputs
- Faulty outdoor sensor or one covered in ice/snow
- Sensor resistance outside the thermistor chart spec
What you can safely check
- Check the outdoor sensor is mounted and free of ice, snow, or debris
- Confirm an outdoor sensor was actually installed (the CHS ships with outdoor reset enabled)
Beyond these checks, do not open the unit or touch gas/electrical parts — BC law requires a licensed gas fitter. Call us for a proper diagnosis.
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Slant/Fin Error Alert 248 / Alert 233 / Hold 96 Repair Across Metro Vancouver
Related Slant/Fin Sensors & Temperature Codes
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