NTI · Boiler

1 P1 Insufficient circulation or missing water (warning)

Normal status TRX

What the display is showing

Supply temperature rising faster than 12.6 °F per second. Warning only.

Applies to: TRX150

Good to know

Low water pressure
Air in the system

Models that show this code

5 models in TRX

TRX085TRX110CTRX150TRX199TRX199C

Other codes on the same units

1 10 CH flow temperature probe open or short circuit
1 12 CH return temperature probe open or short circuit
1 14 External (outdoor) sensor open or short circuit
1 16 Floor thermostat contact open
1 P2 Insufficient circulation or missing water (warning)
1 P3 Inadequate circulation or missing water (warning)
02 01 Damaged or shorted DHW temperature probe
02 03 Storage temperature probe open or short circuit

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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.