diff --git a/configtool/addheaterdlg.py b/configtool/addheaterdlg.py
index b3d782b..c7d2924 100644
--- a/configtool/addheaterdlg.py
+++ b/configtool/addheaterdlg.py
@@ -4,7 +4,8 @@ from configtool.data import BSIZESMALL, offsetChLabel, offsetTcLabel
 
 
 class AddHeaterDlg(wx.Dialog):
-  def __init__(self, parent, names, pins, font):
+  def __init__(self, parent, names, pins, font,
+               name = "", pin = "", pwm = "1"):
     wx.Dialog.__init__(self, parent, wx.ID_ANY, "Add heater", size = (400, 204))
     self.SetFont(font)
     self.Bind(wx.EVT_CLOSE, self.onCancel)
@@ -12,7 +13,7 @@ class AddHeaterDlg(wx.Dialog):
     self.names = names
     self.choices = pins
 
-    self.nameValid = False
+    self.nameValid = (name != "")
 
     sz = wx.BoxSizer(wx.VERTICAL)
     gsz = wx.GridBagSizer()
@@ -24,9 +25,10 @@ class AddHeaterDlg(wx.Dialog):
     st.SetFont(font)
     lsz.Add(st, 1, wx.TOP, offsetTcLabel)
 
-    self.tcName = wx.TextCtrl(self, wx.ID_ANY, "")
+    self.tcName = wx.TextCtrl(self, wx.ID_ANY, name)
     self.tcName.SetFont(font)
-    self.tcName.SetBackgroundColour("pink")
+    if not name:
+      self.tcName.SetBackgroundColour("pink")
     self.tcName.Bind(wx.EVT_TEXT, self.onNameEntry)
     lsz.Add(self.tcName)
     self.tcName.SetToolTipString("Enter a unique name for this heater.")
@@ -42,7 +44,11 @@ class AddHeaterDlg(wx.Dialog):
     self.chPin = wx.Choice(self, wx.ID_ANY, choices = pins)
     self.chPin.SetFont(font)
     self.chPin.Bind(wx.EVT_CHOICE, self.onChoice)
-    self.chPin.SetSelection(0)
+    i = self.chPin.FindString(pin)
+    if i == wx.NOT_FOUND:
+      self.chPin.SetSelection(0)
+    else:
+      self.chPin.SetSelection(i)
     lsz.Add(self.chPin)
     self.chPin.SetToolTipString("Choose a pin for this heater.")
 
@@ -50,6 +56,7 @@ class AddHeaterDlg(wx.Dialog):
 
     self.cbPwm = wx.CheckBox(self, wx.ID_ANY, "PWM")
     self.cbPwm.SetFont(font)
+    self.cbPwm.SetValue(int(pwm) != 0)
     self.cbPwm.SetToolTipString("Use Pulse Width Modulation in case the "
                                 "choosen pin allows to do so.")
 
@@ -66,7 +73,6 @@ class AddHeaterDlg(wx.Dialog):
     self.bSave.SetFont(font)
     self.bSave.Bind(wx.EVT_BUTTON, self.onSave)
     bsz.Add(self.bSave)
-    self.bSave.Enable(False)
 
     bsz.AddSpacer(30, 100)
 
@@ -79,6 +85,7 @@ class AddHeaterDlg(wx.Dialog):
     sz.AddSpacer((10, 10))
     self.SetSizer(sz)
 
+    self.checkDlgValidity()
     self.Fit()
 
   def onNameEntry(self, evt):
diff --git a/configtool/heaterspage.py b/configtool/heaterspage.py
index 783472c..f62932f 100644
--- a/configtool/heaterspage.py
+++ b/configtool/heaterspage.py
@@ -25,23 +25,34 @@ class HeatersPage(wx.Panel, Page):
     sz.AddSpacer((20, 20), pos = (1, 2))
 
     bsz = wx.BoxSizer(wx.VERTICAL)
+
     self.bAdd = wx.Button(self, wx.ID_ANY, "Add", size = BSIZESMALL)
     self.bAdd.SetBackgroundColour(self.deco.getBackgroundColour())
     self.bAdd.SetFont(font)
     self.Bind(wx.EVT_BUTTON, self.doAdd, self.bAdd)
     self.bAdd.SetToolTipString("Add a heater to the configuration.")
-
     bsz.Add(self.bAdd)
 
     bsz.AddSpacer((10, 10))
+
+    self.bModify = wx.Button(self, wx.ID_ANY, "Modify", size = BSIZESMALL)
+    self.bModify.SetBackgroundColour(self.deco.getBackgroundColour())
+    self.bModify.SetFont(font)
+    self.bModify.Enable(False)
+    self.Bind(wx.EVT_BUTTON, self.doModify, self.bModify)
+    self.bModify.SetToolTipString("Modify the selected heater.")
+    bsz.Add(self.bModify)
+
+    bsz.AddSpacer((10, 10))
+
     self.bDelete = wx.Button(self, wx.ID_ANY, "Delete", size = BSIZESMALL)
     self.bDelete.SetBackgroundColour(self.deco.getBackgroundColour())
     self.bDelete.SetFont(font)
     self.bDelete.Enable(False)
     self.Bind(wx.EVT_BUTTON, self.doDelete, self.bDelete)
-    bsz.Add(self.bDelete)
     self.bDelete.SetToolTipString("Remove the selected heater from the "
                                   "configuration.")
+    bsz.Add(self.bDelete)
 
     sz.Add(bsz, pos = (1, 3))
 
@@ -56,8 +67,10 @@ class HeatersPage(wx.Panel, Page):
     self.selection = n
     if n is None:
       self.bDelete.Enable(False)
+      self.bModify.Enable(False)
     else:
       self.bDelete.Enable(True)
+      self.bModify.Enable(True)
 
   def doAdd(self, evt):
     nm = []
@@ -80,6 +93,33 @@ class HeatersPage(wx.Panel, Page):
     self.parent.setHeaters(self.heaters)
     self.assertModified(True)
 
+  def doModify(self, evt):
+    if self.selection is None:
+      return
+
+    nm = []
+    for s in self.heaters:
+      nm.append(s[0])
+
+    h = self.heaters[self.selection]
+
+    dlg = AddHeaterDlg(self, nm, self.validPins, self.font,
+                       name = h[0], pin = h[1], pwm = h[2])
+    rc = dlg.ShowModal()
+    if rc == wx.ID_OK:
+      ht = dlg.getValues()
+
+    dlg.Destroy()
+
+    if rc != wx.ID_OK:
+      return
+
+    self.heaters[self.selection] = ht
+    self.lb.updateList(self.heaters)
+    self.validateTable()
+    self.parent.setHeaters(self.heaters)
+    self.assertModified(True)
+
   def doDelete(self, evt):
     if self.selection is None:
       return