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NTI · Boiler troubleshooting

Prepare the boiler before replacing components

TRX150

What is going on

Before you replace any component on the TRX150, isolate everything: electrical, gas and water. Confirm each one is actually off rather than assuming. Water must not get into the display or control panel, since moisture on the board causes shorts and ruined controls.

Likely causes

  • Power still live at the boiler after only pressing ON/OFF
  • Gas or water valves not fully closed
  • Water dripping onto the display or control panel while draining

Check in this order

  1. Press ON/OFF to turn the boiler off, then switch main power off at the circuit breaker.
  2. Check the boiler electrical connections are tight.
  3. Remove the front cover.
  4. Close the main gas shutoff valve.
  5. Close all water valves (supply, return, inlet and outlet).
  6. Drain the boiler or circuit if needed.
  7. Keep water away from the display and control panel, and cover them if you must open a drain above them.

Applies to: TRX150

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Source: NTI TRX150 manual, p. 98. 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.