Stop timer

I am trying to switch between two routines with a timer. The start works fine however the stoptimer throws a 1004 error. Can anyone point out the obvious (not obvious to me and that's why I am pulling my hair out). Many thanks!

Public activeTimer As Boolean
Public runWhen As Double
Sub rotateRows()
    activeTimer = True
    If activeTimer = True Then
        hideRows
        showRows
    End If
End Sub

Sub hideRows()
ActiveSheet.Rows("2:3").Hidden = true
Application.OnTime Now() + TimeValue("00:00:03"), "hideRows"
End Sub

Sub showRows()
  ActiveSheet.Rows("2:3").Hidden = false
  Application.OnTime Now() + TimeValue("00:00:03"), "showRows"
End Sub

Sub stopTimer()
activeTimer = False
runWhen = Now() + TimeValue("00:00:03")
Application.OnTime EarliestTime:=runWhen, Procedure:="rotateRows", Schedule:=False
End Sub