HVACopediaNTI · Boiler troubleshooting
Burner not running on a call for heat
What is going on
Heat call present but the boiler is not firing.
Likely causes
- Demand already satisfied
- Outlet temperature above setpoint minus on-hysteresis
- A hold, delay or lockout is active
- Burner switch is off in the controller
- Safety setting changed and not yet verified (Lockout 2)
Check in this order
- Check Demand and setpoints on the touchscreen
- Check thermostat and DHW aquastat settings
- Read the Summary page for any Hold, Delay or Lockout code
- If Demand says burner switch off, go to the diagnostics burner test page and turn it on
- For Lockout 2 complete the safety data verification
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.