HVACopediaNTI · Boiler troubleshooting
Boiler bangs or hisses; Lockout 81 delta T
What is going on
Noise and delta-T trips usually mean not enough water flow.
Likely causes
- Insufficient flow
- Scaled or magnetite-coated heat exchanger
- Low system pressure
Check in this order
- Check fuse B and the boiler pump
- Confirm piping matches the piping section and pressure is at least 15 PSI
- Descale the heat exchanger with Fernox DS-40 if scaled
Applies to: Trinity Tft60, Tft85, Tft110, Tft154, Tft201, Tft285, Tft340, Tft399
More boiler guides
Related
Take it to the job
All guides, error codes and tips work offline in the HVACopedia app.
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.