diff --git a/code/modules/atmospherics/machinery/components/binary_devices/circulator.dm b/code/modules/atmospherics/machinery/components/binary_devices/circulator.dm
index b7970389ba8..bf7dc40ae5a 100644
--- a/code/modules/atmospherics/machinery/components/binary_devices/circulator.dm
+++ b/code/modules/atmospherics/machinery/components/binary_devices/circulator.dm
@@ -21,7 +21,7 @@
 	var/mode = CIRCULATOR_HOT
 	var/obj/machinery/power/generator/generator
 
-/obj/machinery/atmospherics/components/unary/shuttle/heater/on_construction(obj_color, set_layer)
+/obj/machinery/atmospherics/components/binary/circulator/on_construction(obj_color, set_layer)
 	var/obj/item/circuitboard/machine/circulator/board = circuit
 	if(board)
 		piping_layer = board.pipe_layer
diff --git a/tgui/packages/tgui/interfaces/ThermalGenerator.js b/tgui/packages/tgui/interfaces/ThermalGenerator.js
index 60721a9d408..c08369480db 100644
--- a/tgui/packages/tgui/interfaces/ThermalGenerator.js
+++ b/tgui/packages/tgui/interfaces/ThermalGenerator.js
@@ -41,17 +41,17 @@ export const ThermalGenerator = (props, context) => {
             </LabeledList.Item>
             <LabeledList.Item label="Power Output">
               <ProgressBar
-                value={power}
+                value={power ?? 0}
                 minValue={0}
                 maxValue={maxPowerDisplay}
                 color="yellow"
               >
-                {formatSiUnit(power, 0, 'W')}
+                {formatSiUnit(power ?? 0, 0, 'W')}
               </ProgressBar>
             </LabeledList.Item>
             <LabeledList.Item label="Cold Loop">
               <ProgressBar
-                value={coldCircTemp}
+                value={coldCircTemp ?? 0}
                 minValue={0}
                 maxValue={600}
                 ranges={{
@@ -60,12 +60,12 @@ export const ThermalGenerator = (props, context) => {
                   average: [500, Infinity],
                 }}
               >
-                {coldCircTemp} K {coldCircPressure} kPa
+                {coldCircTemp ?? 0} K {coldCircPressure ?? 0} kPa
               </ProgressBar>
             </LabeledList.Item>
             <LabeledList.Item label="Hot Loop">
               <ProgressBar
-                value={hotCircTemp}
+                value={hotCircTemp ?? 0}
                 minValue={0}
                 maxValue={600}
                 ranges={{
@@ -74,7 +74,7 @@ export const ThermalGenerator = (props, context) => {
                   average: [500, Infinity],
                 }}
               >
-                {hotCircTemp} K {hotCircPressure} kPa
+                {hotCircTemp ?? 0} K {hotCircPressure ?? 0} kPa
               </ProgressBar>
             </LabeledList.Item>
           </LabeledList>