Userform coding can find data but won't update it

I've been working on a userform that I can use to update information on my spreadsheet but have run into a stumbling block, it will find the information I'm looking for but it won't update it. I've got a seperate userform for entering the data into the spreadsheet and modified its the coding several times to get my search and update userform (different beast altogether now), but keep running into the same problem each time. I've included my file and the coding for the search and update below. I've only managed to learn enough VBA so far to work on this project, so I'm pretty sure I've missed something obvious here.

ThermalTestv2.xlsm

Option Explicit

Private Sub cmdReplace_Click()
Dim rfound As Range, sFind As String
      With Me
        If .txtTime.Value <> "" Then
            sFind = .cboDate.Value
       End If
    End With
    With Sheets(1)
        Set rfound = .Columns(14).Find(what:=sFind, After:=.Cells(1, 14), LookIn:=xlValues _
            , LookAt:=xlWhole, SearchOrder:=xlByRows, SearchDirection:=xlNext)
         Cells.FindNext
        If Not rfound Is Nothing Then
            .Cells(ActiveCell.Row, 2) = Me.txtTime.Text
            .Cells(ActiveCell.Row, 3) = Me.txtChWtrSup.Value
            .Cells(ActiveCell.Row, 4) = Me.txtChWtrRet.Value
            .Cells(ActiveCell.Row, 5) = Me.txtConWtrRet.Value
            .Cells(ActiveCell.Row, 6) = Me.txtConWtrSup.Value
            .Cells(ActiveCell.Row, 7) = Me.txtHeatWtrSup.Value
            .Cells(ActiveCell.Row, 8) = Me.txtHeatWtrRet.Value
            .Cells(ActiveCell.Row, 9) = Me.txtSluHeatSup.Value
            .Cells(ActiveCell.Row, 10) = Me.txtSluHeatRet.Value
            .Cells(ActiveCell.Row, 11) = Me.txtWstHeatSup.Value
            .Cells(ActiveCell.Row, 12) = Me.txtWstHeatRet.Value
            .Cells(ActiveCell.Row, 13) = Me.txtDomHWtrRet.Value
            .Cells(ActiveCell.Row, 14) = Me.txtDomColdWtr.Value
            .Cells(ActiveCell.Row, 15) = Me.txtDomHWtrSup.Value
            .Cells(ActiveCell.Row, 18) = Environ("Username")
            .Cells(ActiveCell.Row, 19) = Now
         End If
         End With
End Sub

Private Sub cmdNext_Click()
 Dim MyName As String, myRange As Range
   With Sheets("Thermals")
   On Error GoTo ende:
    Cells.Find(what:=cboDate.Value, After:=ActiveCell, LookIn:=xlValues, LookAt:= _
        xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, MatchCase:=True _
        , SearchFormat:=True).Activate
        On Error Resume Next
            txtTime.Value = Cells(ActiveCell.Row, 3).Text
            txtChWtrSup.Value = Cells(ActiveCell.Row, 4)
            txtChWtrRet.Value = Cells(ActiveCell.Row, 5)
            txtConWtrRet.Value = Cells(ActiveCell.Row, 6)
            txtConWtrSup.Value = Cells(ActiveCell.Row, 7)
            txtHeatWtrSup.Value = Cells(ActiveCell.Row, 8)
            txtHeatWtrRet.Value = Cells(ActiveCell.Row, 9)
            txtSluHeatSup.Value = Cells(ActiveCell.Row, 10)
            txtSluHeatRet.Value = Cells(ActiveCell.Row, 11)
            txtWstHeatSup.Value = Cells(ActiveCell.Row, 12)
            txtWstHeatRet.Value = Cells(ActiveCell.Row, 13)
            txtDomHWtrRet.Value = Cells(ActiveCell.Row, 14)
            txtDomColdWtr.Value = Cells(ActiveCell.Row, 15)
            txtDomHWtrSup.Value = Cells(ActiveCell.Row, 16)
      End With
ende:
End Sub

Private Sub cboDate_Change()
Dim MyName As String, myRange As Range, found As Object
   MyName = Me.cboDate.Text
   Set myRange = ThisWorkbook.Sheets("Thermals").Range("B:B")
   Set found = myRange.Find(MyName, LookIn:=xlValues, LookAt:=xlWhole)
   If Not found Is Nothing Then
        Me.txtTime = found.Offset(, 1).Text
        Me.txtChWtrSup = found.Offset(, 2)
        Me.txtChWtrRet = found.Offset(, 3)
        Me.txtConWtrRet = found.Offset(, 4)
        Me.txtConWtrSup = found.Offset(, 5)
        Me.txtHeatWtrSup = found.Offset(, 6)
        Me.txtHeatWtrRet = found.Offset(, 7)
        Me.txtSluHeatSup = found.Offset(, 8)
        Me.txtSluHeatRet = found.Offset(, 9)
        Me.txtWstHeatSup = found.Offset(, 10)
        Me.txtWstHeatRet = found.Offset(, 11)
        Me.txtDomHWtrRet = found.Offset(, 12)
        Me.txtDomColdWtr = found.Offset(, 13)
        Me.txtDomHWtrSup = found.Offset(, 14)
   Else
        Me.txtTime = ""
        Me.txtChWtrSup = ""
        Me.txtChWtrRet = ""
        Me.txtConWtrRet = ""
        Me.txtConWtrSup = ""
        Me.txtHeatWtrSup = ""
        Me.txtHeatWtrRet = ""
        Me.txtSluHeatSup = ""
        Me.txtSluHeatRet = ""
        Me.txtWstHeatSup = ""
        Me.txtWstHeatRet = ""
        Me.txtDomHWtrRet = ""
        Me.txtDomColdWtr = ""
        Me.txtDomHWtrSup = ""
      End If
     cmdNext_Click
End Sub

Private Sub UserForm_Initialize()
  cboDate.SetFocus
  Me.cboDate.Value = Format(Date, "Medium Date")
'Populate the Date Combobox
  Dim rngDate As Range
  Dim ws As Worksheet
  Set ws = Worksheets("DateTime")
  For Each rngDate In ws.Range("DateList")
    Me.cboDate.AddItem rngDate.Text
  Next rngDate
End Sub

Private Sub cmdClose_Click()
  Sheets("Thermals").Select
  Unload Me
End Sub

Private Sub UserForm_QueryClose(Cancel As Integer, CloseMode As Integer)
  If CloseMode = vbFormControlMenu Then
    Cancel = True
    MsgBox "Please use the 'Close' button!"
  End If
End Sub

Hi, LoneWolf3574,

maybe use this alternative for updating and build on it:

Private Sub cmdReplace_Click()
Dim sFind As String
Dim var As Variant

If Me.txtTime.Value = "" Then
  Exit Sub
End If
With Worksheets("Thermals")
  var = Application.Match(CDbl(CDate(Me.cboDate.Value)), .Columns(2), 0)
  If Not IsError(var) Then
    Do While CDate(.Cells(var, 3).Value) < CDate(Me.txtTime.Value) And .Cells(var, 2).Value = CDate(Me.cboDate.Value)
      var = var + 1
    Loop
    .Cells(var, 2) = Me.txtTime.Text
    .Cells(var, 3) = Me.txtChWtrSup.Value
    .Cells(var, 4) = Me.txtChWtrRet.Value
    .Cells(var, 5) = Me.txtConWtrRet.Value
    .Cells(var, 6) = Me.txtConWtrSup.Value
    .Cells(var, 7) = Me.txtHeatWtrSup.Value
    .Cells(var, 8) = Me.txtHeatWtrRet.Value
    .Cells(var, 9) = Me.txtSluHeatSup.Value
    .Cells(var, 10) = Me.txtSluHeatRet.Value
    .Cells(var, 11) = Me.txtWstHeatSup.Value
    .Cells(var, 12) = Me.txtWstHeatRet.Value
    .Cells(var, 13) = Me.txtDomHWtrRet.Value
    .Cells(var, 14) = Me.txtDomColdWtr.Value
    .Cells(var, 15) = Me.txtDomHWtrSup.Value
    .Cells(var, 18) = Environ("Username")
    .Cells(var, 19) = Now
  End If
End With
End Sub

Ciao,
Holger