diff --git a/pytec/pytec/gui/model/thermostat.py b/pytec/pytec/gui/model/thermostat.py
index 16e51fc..f2a7fe3 100644
--- a/pytec/pytec/gui/model/thermostat.py
+++ b/pytec/pytec/gui/model/thermostat.py
@@ -34,6 +34,7 @@ class Thermostat(QObject, metaclass=PropertyMeta):
         self._watch_task = None
         self._report_mode_task = None
         self._poll_for_report = True
+        self.connection_errored = False
         super().__init__(parent)
 
     async def run(self):
@@ -50,6 +51,10 @@ class Thermostat(QObject, metaclass=PropertyMeta):
                 self.task = asyncio.create_task(self.update_params())
             await asyncio.sleep(self._update_s)
 
+    @pyqtSlot()
+    def timed_out(self):
+        self.connection_errored = True
+
     async def get_hw_rev(self):
         self.hw_rev = await self._client.hw_rev()
         return self.hw_rev
@@ -100,6 +105,7 @@ class Thermostat(QObject, metaclass=PropertyMeta):
 
     async def end_session(self):
         await self._client.end_session()
+        self.connection_errored = False
 
     async def set_ipv4(self, ipv4):
         await self._client.set_param("ipv4", ipv4)
diff --git a/pytec/tec_qt.py b/pytec/tec_qt.py
index dfee892..4aecf4a 100644
--- a/pytec/tec_qt.py
+++ b/pytec/tec_qt.py
@@ -78,6 +78,9 @@ class MainWindow(QtWidgets.QMainWindow):
             self, self.client, self.report_refresh_spin.value()
         )
 
+        self.client.connection_error.connect(self.thermostat.timed_out)
+        self.client.connection_error.connect(self.bail)
+
         self.autotuners = PIDAutoTuner(self, self.client, 2)
 
         def get_ctrl_panel_config(args):
@@ -197,9 +200,12 @@ class MainWindow(QtWidgets.QMainWindow):
             self.thermostat_ctrl_menu.fan_pwm_warning.setToolTip("")
             self.clear_graphs()
             self.report_box.setChecked(False)
-            if not Thermostat.connecting or Thermostat.connected:
-                for ch in range(self.NUM_CHANNELS):
-                    if self.autotuners.get_state(ch) != PIDAutotuneState.STATE_OFF:
+            for ch in range(self.NUM_CHANNELS):
+                if self.autotuners.get_state(ch) != PIDAutotuneState.STATE_OFF:
+                    if self.thermostat.connection_errored:
+                        # Don't send any commands, just reset local state
+                        self.autotuners.autotuners[ch].setOff()
+                    else:
                         await self.autotuners.stop_pid_from_running(ch)
             await self.thermostat.set_report_mode(False)
             self.thermostat.stop_watching()