diff --git a/src/Thermal/HeatTransfer/sensors.jl b/src/Thermal/HeatTransfer/sensors.jl
index 2282af69..afc4ed44 100644
--- a/src/Thermal/HeatTransfer/sensors.jl
+++ b/src/Thermal/HeatTransfer/sensors.jl
@@ -7,23 +7,18 @@ This is an ideal absolute temperature sensor which returns the temperature of th
 signal. The sensor itself has no thermal interaction with whatever it is connected to. Furthermore, no thermocouple-like
 lags are associated with this sensor model.
 
-# States:
-
-  - `T(t)`: [`K`] Absolute temperature
-
 # Connectors:
 
-  - `port`
+  - `port`: [HeatPort](@ref) Thermal port from which sensor information shall be measured
+  - `T`: [RealOutput](@ref) [K] Absolute temperature of port
 """
 @mtkmodel TemperatureSensor begin
     @components begin
         port = HeatPort()
-    end
-    @variables begin
-        T(t)
+        T = RealOutput()
     end
     @equations begin
-        T ~ port.T
+        T.u ~ port.T
         port.Q_flow ~ 0
     end
 end
@@ -36,25 +31,20 @@ Relative Temperature sensor.
 The relative temperature `port_a.T - port_b.T` is determined between the two ports of this component and is provided as
 output signal in kelvin.
 
-# States:
-
-  - `T(t)`: [`K`] Relative temperature `a.T - b.T`
-
 # Connectors:
 
-  - `port_a`
-  - `port_b`
+  - `port_a`: [HeatPort](@ref) Thermal port from which sensor information shall be measured
+  - `port_b`: [HeatPort](@ref) Thermal port from which sensor information shall be measured
+  - `T`: [RealOutput](@ref) [K] Relative temperature `a.T - b.T`
 """
 @mtkmodel RelativeTemperatureSensor begin
     @components begin
         port_a = HeatPort()
         port_b = HeatPort()
-    end
-    @variables begin
-        T(t)
+        T = RealOutput()
     end
     @equations begin
-        T ~ port_a.T - port_b.T
+        T.u ~ port_a.T - port_b.T
         port_a.Q_flow ~ 0
         port_b.Q_flow ~ 0
     end
@@ -70,26 +60,21 @@ is the amount that passes through this sensor while keeping the temperature drop
 model, so it does not absorb any energy, and it has no direct effect on the thermal response of a system it is included in.
 The output signal is positive, if the heat flows from `port_a` to `port_b`.
 
-# States:
-
-  - `Q_flow(t)`: [`W`] Heat flow from `port_a` to `port_b`
-
 # Connectors:
 
-  - `port_a`
-  - `port_b`
+  - `port_a`: [HeatPort](@ref) Thermal port from which sensor information shall be measured
+  - `port_b`: [HeatPort](@ref) Thermal port from which sensor information shall be measured
+  - `Q_flow`: [RealOutput](@ref) [W] Heat flow from `port_a` to `port_b` 
 """
 @mtkmodel HeatFlowSensor begin
     @components begin
         port_a = HeatPort()
         port_b = HeatPort()
-    end
-    @variables begin
-        Q_flow(t)
+        Q_flow = RealOutput()
     end
     @equations begin
         port_a.T ~ port_b.T
         port_a.Q_flow + port_b.Q_flow ~ 0
-        Q_flow ~ port_a.Q_flow
+        Q_flow.u ~ port_a.Q_flow
     end
 end
diff --git a/test/Thermal/motor.jl b/test/Thermal/motor.jl
index a8f95125..8a8af7e9 100644
--- a/test/Thermal/motor.jl
+++ b/test/Thermal/motor.jl
@@ -1,4 +1,4 @@
-using ModelingToolkit, OrdinaryDiffEqDefault, Test
+using ModelingToolkit, Test
 using ModelingToolkitStandardLibrary.Thermal
 using ModelingToolkitStandardLibrary.Blocks
 
@@ -47,10 +47,10 @@ using ModelingToolkitStandardLibrary.Blocks
 
     # plot(sol; vars=[T_winding.T, T_core.T])
     @test SciMLBase.successful_retcode(sol)
-    @test sol[motor.T_winding.T] == sol[motor.winding.T]
-    @test sol[motor.T_core.T] == sol[motor.core.T]
+    @test sol[motor.T_winding.T.u] == sol[motor.winding.T]
+    @test sol[motor.T_core.T.u] == sol[motor.core.T]
     @test sol[-motor.core.port.Q_flow] ≈
           sol[motor.coreLosses.port.Q_flow + motor.convection.solid.Q_flow + motor.winding2core.port_b.Q_flow]
-    @test sol[motor.T_winding.T][end] >= 500 # not good but better than nothing
-    @test sol[motor.T_core.T] <= sol[motor.T_winding.T]
+    @test sol[motor.T_winding.T.u][end] >= 500 # not good but better than nothing
+    @test sol[motor.T_core.T.u] <= sol[motor.T_winding.T.u]
 end
diff --git a/test/Thermal/piston.jl b/test/Thermal/piston.jl
index 9b915f71..48240d5d 100644
--- a/test/Thermal/piston.jl
+++ b/test/Thermal/piston.jl
@@ -1,4 +1,4 @@
-using ModelingToolkit, OrdinaryDiffEqDefault, Test
+using ModelingToolkit, Test
 using ModelingToolkitStandardLibrary.Thermal
 using ModelingToolkitStandardLibrary.Blocks
 
diff --git a/test/Thermal/thermal.jl b/test/Thermal/thermal.jl
index 43137d9d..8e53e34a 100644
--- a/test/Thermal/thermal.jl
+++ b/test/Thermal/thermal.jl
@@ -29,7 +29,7 @@ using OrdinaryDiffEq: ReturnCode.Success
     # Check if Relative temperature sensor reads the temperature of heat capacitor
     # when connected to a thermal conductor and a fixed temperature source
     @test SciMLBase.successful_retcode(sol)
-    @test sol[reltem_sensor.T] + sol[tem_src.port.T] == sol[mass1.T] + sol[th_conductor.dT]
+    @test sol[reltem_sensor.T.u] + sol[tem_src.port.T] == sol[mass1.T] + sol[th_conductor.dT]
 
     @info "Building a two-body system..."
     eqs = [connect(T_sensor1.port, mass1.port, th_conductor.port_a)
@@ -49,8 +49,8 @@ using OrdinaryDiffEq: ReturnCode.Success
     m1, m2 = sol.u[end]
     @test m1≈m2 atol=1e-1
     mass_T = reduce(hcat, sol.u)
-    @test sol[T_sensor1.T] == mass_T[1, :]
-    @test sol[T_sensor2.T] == mass_T[2, :]
+    @test sol[T_sensor1.T.u] == mass_T[1, :]
+    @test sol[T_sensor2.T.u] == mass_T[2, :]
 end
 
 # Test HeatFlowSensor, FixedHeatFlow, ThermalResistor, ThermalConductor
@@ -81,7 +81,7 @@ end
 
     @test SciMLBase.successful_retcode(sol)
     @test sol[th_conductor.dT] .* G == sol[th_conductor.Q_flow]
-    @test sol[th_conductor.Q_flow] ≈ sol[hf_sensor1.Q_flow] + sol[flow_src.port.Q_flow]
+    @test sol[th_conductor.Q_flow] ≈ sol[hf_sensor1.Q_flow.u] + sol[flow_src.port.Q_flow]
 
     @test sol[mass1.T] == sol[th_resistor.port_a.T]
     @test sol[th_resistor.dT] ./ R ≈ sol[th_resistor.Q_flow]