diff --git a/homeassistant/components/broadlink/sensor.py b/homeassistant/components/broadlink/sensor.py
index 0e42d8c438f..3f4a1e861b3 100644
--- a/homeassistant/components/broadlink/sensor.py
+++ b/homeassistant/components/broadlink/sensor.py
@@ -51,7 +51,7 @@ async def async_setup_entry(hass, config_entry, async_add_entities):
     sensors = [
         BroadlinkSensor(device, monitored_condition)
         for monitored_condition in sensor_data
-        if sensor_data[monitored_condition] or device.api.type == "A1"
+        if sensor_data[monitored_condition] != 0 or device.api.type == "A1"
     ]
     async_add_entities(sensors)
 
diff --git a/homeassistant/components/broadlink/updater.py b/homeassistant/components/broadlink/updater.py
index 8401dba8c0d..a84eec07d68 100644
--- a/homeassistant/components/broadlink/updater.py
+++ b/homeassistant/components/broadlink/updater.py
@@ -117,11 +117,25 @@ class BroadlinkRMUpdateManager(BroadlinkUpdateManager):
         device = self.device
 
         if hasattr(device.api, "check_sensors"):
-            return await device.async_request(device.api.check_sensors)
+            data = await device.async_request(device.api.check_sensors)
+            return self.normalize(data, self.coordinator.data)
 
         await device.async_request(device.api.update)
         return {}
 
+    @staticmethod
+    def normalize(data, previous_data):
+        """Fix firmware issue.
+
+        See https://github.com/home-assistant/core/issues/42100.
+        """
+        if data["temperature"] == -7:
+            if previous_data is None or previous_data["temperature"] is None:
+                data["temperature"] = None
+            elif abs(previous_data["temperature"] - data["temperature"]) > 3:
+                data["temperature"] = previous_data["temperature"]
+        return data
+
 
 class BroadlinkSP1UpdateManager(BroadlinkUpdateManager):
     """Manages updates for Broadlink SP1 devices."""
diff --git a/tests/components/broadlink/test_device.py b/tests/components/broadlink/test_device.py
index df22bcaffcb..8e53fd74c1c 100644
--- a/tests/components/broadlink/test_device.py
+++ b/tests/components/broadlink/test_device.py
@@ -144,7 +144,10 @@ async def test_device_setup_update_authorization_error(hass):
     """Test we handle an authorization error in the update step."""
     device = get_device("Office")
     mock_api = device.get_mock_api()
-    mock_api.check_sensors.side_effect = (blke.AuthorizationError(), None)
+    mock_api.check_sensors.side_effect = (
+        blke.AuthorizationError(),
+        {"temperature": 30},
+    )
 
     with patch.object(
         hass.config_entries, "async_forward_entry_setup"
diff --git a/tests/components/broadlink/test_sensors.py b/tests/components/broadlink/test_sensors.py
index de0cd88f288..e5d31705a4f 100644
--- a/tests/components/broadlink/test_sensors.py
+++ b/tests/components/broadlink/test_sensors.py
@@ -143,6 +143,38 @@ async def test_rm_pro_sensor_update(hass):
     assert sensors_and_states == {(f"{device.name} Temperature", "25.8")}
 
 
+async def test_rm_pro_filter_crazy_temperature(hass):
+    """Test we filter a crazy temperature variation.
+
+    Firmware issue. See https://github.com/home-assistant/core/issues/42100.
+    """
+    device = get_device("Office")
+    mock_api = device.get_mock_api()
+    mock_api.check_sensors.return_value = {"temperature": 22.9}
+
+    device_registry = mock_device_registry(hass)
+    entity_registry = mock_registry(hass)
+
+    mock_api, mock_entry = await device.setup_entry(hass, mock_api=mock_api)
+
+    device_entry = device_registry.async_get_device({(DOMAIN, mock_entry.unique_id)})
+    entries = async_entries_for_device(entity_registry, device_entry.id)
+    sensors = {entry for entry in entries if entry.domain == SENSOR_DOMAIN}
+    assert len(sensors) == 1
+
+    mock_api.check_sensors.return_value = {"temperature": -7}
+    await hass.helpers.entity_component.async_update_entity(
+        next(iter(sensors)).entity_id
+    )
+    assert mock_api.check_sensors.call_count == 2
+
+    sensors_and_states = {
+        (sensor.original_name, hass.states.get(sensor.entity_id).state)
+        for sensor in sensors
+    }
+    assert sensors_and_states == {(f"{device.name} Temperature", "22.9")}
+
+
 async def test_rm_mini3_no_sensor(hass):
     """Test we do not set up sensors for RM mini 3."""
     device = get_device("Entrance")