HVACopediaNTI · Boiler
Hold 78 Demand lost in run
What the control is telling you
Demand lost in run.
Applies to: Trinity Tft60, Tft85, Tft110, Tft154, Tft201, Tft285, Tft340, Tft399
Models that show this code
13 models in Trinity Tft
Other codes on the same units
- Hold 7 Internal fault: Safety relay drive error
- Hold 70 Wait for leakage test completion
- Hold 70 Wait for leakage test completion
- Hold 78 Demand lost in run
- Hold 8 Internal fault: Zero crossing not detected
- Hold 8 Internal fault: Zero crossing not detected
- Hold 91 Inlet sensor fault
- Hold 91 Inlet sensor fault
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Source: NTI Trinity Tft399 Installation and Operation Manual (2018-09-07), Sec. 16.0 Troubleshooting, Table 16-3. Summarized in our own words; check the original manual for your model.
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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.