diff --git a/tasks/tempctrl.py b/tasks/tempctrl.py
index 0ac0354..21d50b1 100644
--- a/tasks/tempctrl.py
+++ b/tasks/tempctrl.py
@@ -78,5 +78,19 @@ class TcTask(ATask):
 			# would otherwise raise.
 			if self.tc.is_configured():
 				self.tc.process()
+			else:
+				# Smith's model plant params only ever arrive from a Sud's
+				# doc (see brewpi.py), so right after server start - before
+				# any Sud has ever loaded - is_configured() stays False and
+				# process() never runs. Without this, theta_ist/
+				# heatrate_ist/heatrate_soll (and thus the 'Ist'/'Soll'
+				# messages below) would stay frozen at their __init__
+				# defaults forever, leaving the GUI's Ist Temp/Rate and
+				# Soll Rate displays blank on connect. Mirror the raw
+				# sensor reading straight through instead - there's no
+				# controller output yet to report a real rate for.
+				self.tc.theta_ist = self.tc.get_theta_ist_set()
+				self.tc.heatrate_ist = 0.0
+				self.tc.heatrate_soll = 0.0
 			await asyncio.sleep(self.interval)