Try:

'This is worksheet event code, which means that it needs to be
'placed in the appropriate worksheet code module, not a standard
'code module. To do this, right-click on the sheet tab, select
'the View Code option from the menu, and paste the code in.

'-----------------------------------------------------------------
Private Sub Worksheet_Change(ByVal Target As Range)
'-----------------------------------------------------------------
Const WS_RANGE As String = "H1:H10"    '<=== change to suit

   check_words = Array("word", "tank set")  '<=== set to your words/phrases
   On Error GoTo ws_exit:
   Application.EnableEvents = False
   If Not Intersect(Target, Me.Range(WS_RANGE)) Is Nothing Then
       With Target
           For i = LBound(check_words) To UBound(check_words)
           If InStr(1, .Value, check_words(i)) Then
               Select Case i + 1
                   Case 1: .Interior.ColorIndex = 3    'red
                   Case 2: .Interior.ColorIndex = 6    'yellow
                   Case 3: .Interior.ColorIndex = 5    'blue
                   Case 4: .Interior.ColorIndex = 10   'green
               End Select
           GoTo ws_exit
           End If
           Next i
           
           
       End With
   End If

ws_exit:
   Application.EnableEvents = True
End Sub

You should use a macro to paint the colors rather than Conditional Formatting.