diff --git a/client/brewpi_gui.py b/client/brewpi_gui.py
index dbead21..a067baf 100755
--- a/client/brewpi_gui.py
+++ b/client/brewpi_gui.py
@@ -489,7 +489,14 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 					self.plot_temp_soll = submsg['Temp']
 					self.lcdNumber_temp_soll.display(str(submsg['Temp']))
 					if self.slider_temp_soll_initial_update:
+						# blockSignals: setValue() here is just syncing the
+						# slider's display to the server's current value, not
+						# a user edit - without this it would also fire
+						# valueChanged and echo the value straight back as a
+						# command.
+						self.Slider_temp_soll.blockSignals(True)
 						self.Slider_temp_soll.setValue(int(round(submsg['Temp'])))
+						self.Slider_temp_soll.blockSignals(False)
 						self.slider_temp_soll_initial_update = False
 				if 'Rate' in submsg:
 					subsubmsg = submsg['Rate']
@@ -500,7 +507,9 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 						if "Set" in subkey:
 							if self.heatrate_soll_initial_update:
 								self.heatrate_soll_initial_update = False
+								self.doubleSpinBox_heatrate_soll.blockSignals(True)
 								self.doubleSpinBox_heatrate_soll.setValue(subsubmsg['Set'])
+								self.doubleSpinBox_heatrate_soll.blockSignals(False)
 			if "Ist" in key:
 				submsg = msg['Ist']
 				if 'Temp' in submsg:
@@ -515,7 +524,9 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 		for key in msg:
 			if "Activate" in key:
 				if self.checkbox_heater_activate_initial_update:
+					self.checkbox_heater_activate.blockSignals(True)
 					self.checkbox_heater_activate.setCheckState(2 if msg['Activate'] == 1 else 0)
+					self.checkbox_heater_activate.blockSignals(False)
 					self.checkbox_heater_activate_initial_update = False
 			elif "PowerSet" in key:
 				self.plot_power_set = msg['PowerSet']
@@ -523,7 +534,16 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 				self.plot_power_eff = msg['Power']
 				self.lcdNumber_power_heater.display(msg['Power'])
 				if self.slider_pwr_initial_update:
+					# blockSignals: this is a display-only sync of the
+					# slider to the heater's current power, not a manual
+					# override - letting valueChanged fire here would echo
+					# it back as {'Power': ...}, which tasks/heater.py's
+					# power_soll = max(power_soll, power_actor) latches as a
+					# floor that never goes back down on its own. That's the
+					# "stale power > 0 after reconnect" bug.
+					self.Slider_pwr_soll.blockSignals(True)
 					self.Slider_pwr_soll.setValue(int(round(msg['Power'])))
+					self.Slider_pwr_soll.blockSignals(False)
 					self.slider_pwr_initial_update = False
 			elif "Capabilities" in key:
 				submsg = msg['Capabilities']
@@ -537,11 +557,15 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 		for key in msg:
 			if "Activate" in key:
 				if self.checkbox_stirrer_activate_initial_update:
+					self.checkbox_stirrer_activate.blockSignals(True)
 					self.checkbox_stirrer_activate.setCheckState(2 if msg['Activate'] == 1 else 0)
+					self.checkbox_stirrer_activate.blockSignals(False)
 					self.checkbox_stirrer_activate_initial_update = False
 			elif "Speed" in key:
 				if self.slider_speed_initial_update:
+					self.Slider_speed_soll.blockSignals(True)
 					self.Slider_speed_soll.setValue(int(round(msg['Speed'])))
+					self.Slider_speed_soll.blockSignals(False)
 					self.slider_speed_initial_update = False
 			elif "Capabilities" in key:
 				submsg = msg['Capabilities']