HVACopedia

NTI · Boiler troubleshooting

Low water cutoff / ILK OFF lockout (67)

Trinity Tft

What is going on

Burner will not fire and display reads ILK OFF.

Likely causes

  • Low water in boiler
  • External limit open

Check in this order

  1. Check water level and the internal low water cutoff
  2. Check any external limit wired between R and LIM

Applies to: Trinity Tft60, Tft85, Tft110, Tft155, Tft175, Tft200, Tft250, Tft300, Tft399

More boiler guides

Related

NTI tips · Calculators and reference tables

Take it to the job

All guides, error codes and tips work offline in the HVACopedia app.

Open the app

Source: NTI Tft60-399 Installation and Operation Instructions (rev. 2012-04-09), Sec. 15.0 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.