HVACopediaNTI · Boiler troubleshooting
Circulator (CH or DHW) not running
What is going on
Pump output not powering the circulator.
Likely causes
- Blown fuse B (PUMP A and C) or fuse A (PUMP B)
- Control output dead
- Circulator failed
Check in this order
- Check fuse B (and fuse A for the boiler pump)
- On the pump diagnostic page, switch the pump on manually and check for 120 VAC at the pump terminals on the line voltage strip
- If no 120 VAC, replace the control; if voltage is present and the pump will not turn, replace the pump
Applies to: Trinity Tft60, Tft85, Tft110, Tft154, Tft201, Tft285, Tft340, Tft399
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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.