HVACopediaNTI · Boiler troubleshooting
Outdoor temperature alert (Alert 248)
What is going on
Controller expects an outdoor sensor because outdoor reset is on from the factory.
Likely causes
- Sensor not connected
- Wiring on wrong terminals
- Faulty or iced-up sensor
Check in this order
- Connect the outdoor sensor or switch outdoor reset off
- Wires belong on OUTDOOR and COM
- Check the sensor is free of ice and snow and compare resistance with the thermistor chart
Applies to: Trinity Tft60, Tft85, Tft110, Tft154, Tft201, Tft285, Tft340, Tft399
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Source: NTI Trinity Tft399 Installation and Operation Manual (2018-09-07), Sec. 16.0 Troubleshooting. Written in our own words; check the manual for your exact model.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.