After some experimenting, this is what worked:
Code:
Private Sub btnDefaultNoneOn_Click()
On Error GoTo Err_btnDefaultNoneOn_Click
Me.og3.Value = Me.og3.DefaultValue
Me.og4.Value = Me.og4.DefaultValue
Me.og5.Value = Me.og5.DefaultValue
Me.og6.Value = Me.og6.DefaultValue
Me.og7.Value = Me.og7.DefaultValue
Me.og8.Value = Me.og8.DefaultValue
Me.og9.Value = Me.og9.DefaultValue
Exit_btnDefaultNoneOn_Click:
Exit Sub
Err_btnDefaultNoneOn_Click:
MsgBox Err.Description
Resume Exit_btnDefaultNoneOn_Click
End Sub
Using your ".Value" suggestion and enclosing the number in quotes also works.
Thanks for your input!