diff --git a/pykirdy/kirdy_qt.py b/pykirdy/kirdy_qt.py
index c9cf676..e40f009 100644
--- a/pykirdy/kirdy_qt.py
+++ b/pykirdy/kirdy_qt.py
@@ -216,15 +216,21 @@ class Graphs:
                 self._pd_mon_pwr_plot.hide()
                 self.pd_mon_pwr_connector.cb_append_data_point(0.0, ts)
 
-            if tec_temp is not None:
-                self.tec_temp_connector.cb_append_data_point(tec_temp, ts)
-                if self._temp_setpoint_line.isVisible():
-                    self.tec_setpoint_connector.cb_append_data_point(self._temp_setpoint_line.value(), ts)
-                else:
-                    self.tec_setpoint_connector.cb_append_data_point(tec_temp, ts)
-                if tec_i_measure is not None:
-                    self.tec_i_measure_connector.cb_append_data_point(tec_i_measure, ts)
-                self.tec_i_target_connector.cb_append_data_point(tec_i_set, ts)
+            if tec_temp is None:
+                self._tec_temp_plot.hide()
+                tec_temp = -273.15
+            else:
+                self._tec_temp_plot.show()
+
+            self.tec_temp_connector.cb_append_data_point(tec_temp, ts)
+            if self._temp_setpoint_line.isVisible():
+                self.tec_setpoint_connector.cb_append_data_point(self._temp_setpoint_line.value(), ts)
+            else:
+                self.tec_setpoint_connector.cb_append_data_point(tec_temp, ts)
+            if tec_i_measure is not None:
+                self.tec_i_measure_connector.cb_append_data_point(tec_i_measure, ts)
+            self.tec_i_target_connector.cb_append_data_point(tec_i_set, ts)
+
         except Exception as e:
             logging.error(f"Graph Value cannot be updated. Data:{report}", exc_info=True)
 
@@ -857,7 +863,10 @@ class MainWindow(QtWidgets.QMainWindow):
                 self.params[2].child('Power').setValue('g' if report['pwr_on'] else 'w')
                 self.params[2].child('Alarm').setValue('r' if report['temp_mon_status']['over_temp_alarm'] else 'w')
             with QSignalBlocker(self.params[3]):
-                self.params[3].child('Readings', 'Temperature').setValue(report["temperature"])
+                if report["temperature"] == None:
+                    self.params[3].child('Readings', 'Temperature').setValue(-273.15)
+                else:
+                    self.params[3].child('Readings', 'Temperature').setValue(report["temperature"])
                 self.params[3].child('Readings', 'Current through TEC').setValue(report["tec_i"])
         except Exception as e:
             logging.error(f"Params tree cannot be updated. Data:{report}", exc_info=True)