HVACopediaNTI · Boiler
01 01 Overheat (CH circuit)
What the control is telling you
Central heating circuit overheat. Clears with a manual reset.
Applies to: TRX150
Test and repair steps
- Press Reset to clear the code.
- If it returns, check that the supply and return temperature probes work and are positioned correctly.
- Check that the circulation pump works and is positioned correctly.
- Check the water pressure on the pressure gauge.
Models that show this code
5 models in TRX
Other codes on the same units
- 01 03 Insufficient circulation or low water pressure
- 01 04 Insufficient circulation or low water pressure
- 01 05 Insufficient circulation or low water pressure
- 01 06 Insufficient circulation or low water pressure
- 01 07 Insufficient circulation or water
- 01 08 Low water pressure lockout (water pressure switch)
- 1 10 CH flow temperature probe open or short circuit
- 1 12 CH return temperature probe open or short circuit
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Source: NTI TRX150 manual, p. 90. Summarized in our own words; check the original manual for your model.
Homeowner looking at this code? See what it means for you and when to call a technician.
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.