diff --git a/bundles/org.openhab.binding.panasoniccomfortcloud/src/main/java/org/openhab/binding/panasoniccomfortcloud/internal/handler/PanasonicComfortCloudAirconditionHandler.java b/bundles/org.openhab.binding.panasoniccomfortcloud/src/main/java/org/openhab/binding/panasoniccomfortcloud/internal/handler/PanasonicComfortCloudAirconditionHandler.java
index c8cb9e69b7427..838c080d7deef 100644
--- a/bundles/org.openhab.binding.panasoniccomfortcloud/src/main/java/org/openhab/binding/panasoniccomfortcloud/internal/handler/PanasonicComfortCloudAirconditionHandler.java
+++ b/bundles/org.openhab.binding.panasoniccomfortcloud/src/main/java/org/openhab/binding/panasoniccomfortcloud/internal/handler/PanasonicComfortCloudAirconditionHandler.java
@@ -268,8 +268,12 @@ private void handleVerticalSwingCommand(ChannelUID channelUID, Command command,
 
     private void handleTargetTemperatureCommand(ChannelUID channelUID, Command command, Device device) {
         if (command instanceof RefreshType) {
-            updateState(channelUID, new QuantityType<>(device.getCurrentParameters().getTargetTemperature(),
-                    device.getTemperatureUnit()));
+            if (device.getCurrentParameters().getTargetTemperature() == null) {
+                updateState(channelUID, UnDefType.UNDEF);
+            } else {
+                updateState(channelUID, new QuantityType<>(device.getCurrentParameters().getTargetTemperature(),
+                        device.getTemperatureUnit()));
+            }
         } else {
             double targetTemperature = -1;
             if (command instanceof QuantityType) {
@@ -361,7 +365,6 @@ private void handleCurrentOutdoorTemperatureCommand(ChannelUID channelUID, Comma
     private void sendParameters(ChannelUID channelUID, Device device, Parameters newParameters,
             State newStateIfSuccessfulUpdate) {
         try {
-
             SetDevicePropertiesResponse rsp = accountHandler.getApiBridge().sendRequest(
                     new SetDevicePropertiesRequest(device.getDeviceId(), newParameters.toParametersDTO(device)),
                     SetDevicePropertiesResponse.class);
diff --git a/bundles/org.openhab.binding.panasoniccomfortcloud/src/main/java/org/openhab/binding/panasoniccomfortcloud/internal/model/Parameters.java b/bundles/org.openhab.binding.panasoniccomfortcloud/src/main/java/org/openhab/binding/panasoniccomfortcloud/internal/model/Parameters.java
index fd34e44a3cfb8..1d847a7e9b58c 100644
--- a/bundles/org.openhab.binding.panasoniccomfortcloud/src/main/java/org/openhab/binding/panasoniccomfortcloud/internal/model/Parameters.java
+++ b/bundles/org.openhab.binding.panasoniccomfortcloud/src/main/java/org/openhab/binding/panasoniccomfortcloud/internal/model/Parameters.java
@@ -12,7 +12,8 @@
  */
 package org.openhab.binding.panasoniccomfortcloud.internal.model;
 
-import org.openhab.binding.panasoniccomfortcloud.internal.BindingConstants;
+import java.util.Set;
+
 import org.openhab.binding.panasoniccomfortcloud.internal.dto.ParametersDTO;
 
 /**
@@ -20,7 +21,7 @@
  */
 public class Parameters {
 
-    public static final int INVALID_TEMPERATURE_READING = 126;
+    public static final Set<Object> INVALID_TEMPERATURE_READINGS = Set.of(126, -255);
     private Parameters shadowParameters = null;
     private AirSwingUpDown swingUpDown;
     private AirSwingSideways airSwingSideways;
@@ -55,18 +56,14 @@ public Parameters(ParametersDTO dto, Device device) {
         nanoeMode = NanoeMode.parseValue(dto.nanoe);
         actualNanoeMode = NanoeMode.parseValue(dto.actualNanoe);
         masterSwitch = dto.operate != null && dto.operate != 0;
-        targetTemperature = dto.temperatureSet;
-
-        if (BindingConstants.DEVICE_TYPE_WIFI_DONGLE.equals(device.getType())) {
-            // Bug in WiFi dongles reporting invalid temperature
-            if (dto.insideTemperature != INVALID_TEMPERATURE_READING) {
-                insideTemperature = dto.insideTemperature;
-            }
-            if (dto.outTemperature != INVALID_TEMPERATURE_READING) {
-                outsideTemperature = dto.outTemperature;
-            }
-        } else {
+
+        if (!INVALID_TEMPERATURE_READINGS.contains(dto.temperatureSet)) {
+            targetTemperature = dto.temperatureSet;
+        }
+        if (!INVALID_TEMPERATURE_READINGS.contains(dto.insideTemperature)) {
             insideTemperature = dto.insideTemperature;
+        }
+        if (!INVALID_TEMPERATURE_READINGS.contains(dto.outTemperature)) {
             outsideTemperature = dto.outTemperature;
         }
 
diff --git a/bundles/org.openhab.binding.panasoniccomfortcloud/src/main/java/org/openhab/binding/panasoniccomfortcloud/internal/model/TemperatureRange.java b/bundles/org.openhab.binding.panasoniccomfortcloud/src/main/java/org/openhab/binding/panasoniccomfortcloud/internal/model/TemperatureRange.java
deleted file mode 100644
index 72945e8b29739..0000000000000
--- a/bundles/org.openhab.binding.panasoniccomfortcloud/src/main/java/org/openhab/binding/panasoniccomfortcloud/internal/model/TemperatureRange.java
+++ /dev/null
@@ -1,46 +0,0 @@
-/**
- * Copyright (c) 2010-2022 Contributors to the openHAB project
- *
- * See the NOTICE file(s) distributed with this work for additional
- * information.
- *
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Public License 2.0 which is available at
- * http://www.eclipse.org/legal/epl-2.0
- *
- * SPDX-License-Identifier: EPL-2.0
- */
-package org.openhab.binding.panasoniccomfortcloud.internal.model;
-
-/**
- * @author Arne Seime - Initial contribution
- */
-public class TemperatureRange {
-    private static final int DEFAULT_MIN = 16;
-    private static final int DEFAULT_MAX = 30;
-
-    private int min;
-    private int max;
-
-    public TemperatureRange(int min, int max) {
-        this.min = set(min, DEFAULT_MIN);
-        this.max = set(max, DEFAULT_MAX);
-    }
-
-    private int set(int value, int defaultValue) {
-        if (value == -1) {
-            return defaultValue;
-        } else {
-            return value;
-        }
-    }
-
-    public boolean isValid(double targetValue) {
-        return targetValue >= min && targetValue <= max;
-    }
-
-    @Override
-    public String toString() {
-        return "TemperatureRange{" + "min=" + min + ", max=" + max + '}';
-    }
-}