Error Message—Heat Transfer = Off – no or insufficient Temperature Boundary Condition

Issue

Heat Transfer was enabled on the Solve dialog, but this error is issued: 

Heat Transfer = OFF - no or insufficient BC

Solution

A persistent temperature must be applied somewhere on the analysis model when heat transfer is enabled. The best condition is a temperature boundary condition. A film coefficient or radiation boundary condition can also be used because both have a reference temperature. It is a good idea to specify a temperature boundary condition for any heat transfer analysis, but either of these other conditions can be used without a specified temperature.

A temperature initial condition without a temperature boundary condition is not sufficient. The value does not remain specified on the model after the initial iteration or time step, so its effect does not persist throughout the simulation. 

For transient analyses, if a transient temperature boundary condition is used, be sure that the time curve defines a temperature value through the time-line of the analysis.

A heat transfer analysis with heat generation or heat flux conditions that does not include a persistent temperature condition is subject to "thermal run-away." This means that the thermal solution can simply keep changing (driving the temperature upward) without any bounds. This occurs because the analysis does not have a reference temperature in the form of a temperature boundary condition. 

To resolve this error: 

Apply a temperature boundary condition to the model. A film coefficient or radiation boundary condition is also suitable.