Verify boundary conditions.
In the Outline view under Setup, expand Boundary Conditions / Wall.
Double-click the convective-boundary object.
The Wall dialog opens.
On the Thermal tab under Thermal Conditions, verify the following values:
Convection is selected (this is the conductive boundary condition).
Heat Transfer Coefficient is set to 10.
Free Stream Temperature is set to 293.15.
Click Close to exit the dialog.