How to use Sum in an IF Statement in VBA

All i'm trying to do is find out if a range is > 0 using VBA but i'm having trouble with summing the range, when I run it I get the error 438

Here is my Code;

If cbAC.Value = True And Sheets("Cost Sheet").Sum(Range(Cells(25, 4), Cells(30, 4))).Value > 0 Then