Hold / Lockout 79 Outlet high limit

What the control is telling you

Outlet water temperature reached the outlet high limit setting.

Applies to: Trinity Tft60, Tft85, Tft110, Tft154, Tft201, Tft285, Tft340, Tft399

Likely causes

• CH or DHW setpoint plus off hysteresis is above the high limit (factory limit 200 F / 93 C)
• CH or DHW pump not working
• Outlet high limit set too low
• Outlet high limit response set to lock out

Test and repair steps

1. Compare setpoint plus off hysteresis with the high limit and lower the setpoint if needed
2. Check the CH and DHW pumps
3. Raise the outlet high limit (maximum 200 F / 93 C)
4. Set the outlet high limit response to recycle and hold unless local code forbids it, so the boiler does not lock out

Models that show this code

13 models in Trinity Tft

Other codes on the same units

• Hold / Lockout 243 Invalid UV with spark interference not compatible with Igniter on throughout
• Hold / Lockout 67 ILK off - interlock string open
• Hold / Lockout 67 ILK off - interlock string open
• Hold / Lockout 79 Outlet high limit
• Hold / Lockout 81 Delta T limit
• Hold / Lockout 81 Delta T limit
• Hold / Lockout 85 Inlet/outlet inversion limit
• Hold / Lockout 85 Inlet/outlet inversion limit