NTI sequences of operation

14 sequences for NTI equipment: what the unit does, step by step, with the timings. Pick the equipment type, then the mode.

Boiler (14)

Startup

• Combustion checking procedure
  TRX
• Power-on and mode sequence
  TRX
• Power-up and what lets the boiler start a call
  Trinity Tft

Ignition

• Failed ignition and lockout
  TRX150
• First ignition start-up
  TRX
• Light-off sequence and retries
  Trinity Tft

Heating

• Central heat call (CH1) from call to satisfied
  Trinity Tft

Domestic hot water

• Indirect tank (DHW) call
  Trinity Tft

Pump/purge

• Circulator outputs and their fuses
  Trinity Tft

Freeze protection

• Freeze protection stages
  TRX

Standby/shutdown

• Demand satisfied and shutdown
  Trinity Tft
• Normal shutdown
  TRX150

Other

• Lead-lag (cascade) demand handling
  Trinity Tft
• Safety stops, holds and lockouts
  Trinity Tft

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.