HVACopediaNTI · Boiler
Hold 28 Internal fault: A/D linearity test fails
What the control is telling you
Control board self-check reported an internal problem: A/D linearity test fails.
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 26 Internal fault: Static flame ripple
- Hold 27 Flame rod shorted to ground
- Hold 27 Flame rod shorted to ground
- Hold 28 Internal fault: A/D linearity test fails
- Hold 29 Internal fault: Flame bias cannot be set in range
- Hold 29 Internal fault: Flame bias cannot be set in range
- Hold 3 Internal fault: Hardware fault
- Hold 3 Internal fault: Hardware 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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