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NTI · Boiler

4 30 Detected accessory wired to BUS connection

Normal status TRX

What the display is showing

An accessory is detected on the BUS connection. Warning.

Applies to: TRX150

Good to know

  • Accessory wired to BUS without the matching setting

What to do

  1. If an NTI zone controller is connected to the BUS connection, make sure parameter 11.0.0 is set to 1.

Models that show this code

5 models in TRX

TRX085TRX110CTRX150TRX199TRX199C

Other codes on the same units

  • 3 P9 Scheduled maintenance: call for service
  • 4 11 Room sensor open or short circuit, Zone 1
  • 4 12 Room sensor open or short circuit, Zone 2
  • 4 13 Room sensor open or short circuit, Zone 3
  • 4 31 Code 431 (no description printed)
  • 05 01 Ignition lockout after 3 failed attempts
  • 05 02 Flame detected with gas valve closed
  • 05 04 10 flame lifts in one operating cycle

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Source: NTI TRX150 manual, p. 91. Summarized in our own words; check the original manual for your 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.