diff --git a/zhaquirks/bosch/thermostat.py b/zhaquirks/bosch/thermostat.py
new file mode 100644
index 0000000000..2ef8329669
--- /dev/null
+++ b/zhaquirks/bosch/thermostat.py
@@ -0,0 +1,164 @@
+"""Device handler for Bosch thermostats."""
+from typing import Final
+
+import zigpy.types as t
+
+from zigpy.profiles import zha
+from zigpy.quirks import CustomDevice
+from zigpy.zcl.clusters.general import Basic, Identify, Groups, Ota, PollControl, Time
+from zigpy.zcl.clusters.homeautomation import Diagnostic
+from zigpy.zcl.clusters.hvac import Thermostat, UserInterface
+from zigpy.zcl.foundation import ZCLAttributeDef
+
+from zhaquirks import PowerConfigurationCluster
+from zhaquirks.bosch import BOSCH
+from zhaquirks.const import (
+    DEVICE_TYPE,
+    ENDPOINTS,
+    INPUT_CLUSTERS,
+    MODELS_INFO,
+    OUTPUT_CLUSTERS,
+    PROFILE_ID,
+)
+
+MANUFACTURER_ID = 0x1209
+
+SCREEN_ORIENTATION = 0x400b
+DISPLAY_MODE = 0x4039
+SCREEN_TIMEOUT = 0x403a
+SCREEN_BRIGHTNESS = 0x403b
+
+WINDOW_OPEN = 0x4042
+BOOST = 0x4043
+SYSTEM_MODE = 0x4007
+VALVE_POSITION = 0x4020
+REMOTE_TEMPERATURE = 0x4040
+
+
+class ScreenOrientation(t.uint8_t):
+    Normal = 0x00
+    Flipped = 0x01
+
+
+class DisplayMode(t.enum8):
+    Target = 0x00
+    Measured = 0x01
+
+
+class ScreenTimeout(t.enum8):
+    pass
+
+
+class ScreenBrightness(t.enum8):
+    pass
+
+
+class WindowOpen(t.enum8):
+    Closed = 0x00
+    Open = 0x01
+
+
+class SystemMode(t.enum8):
+    Auto = 0x00
+    Heat = 0x01
+    Off = 0x05
+
+
+class BoschHvacUserInterface(UserInterface):
+    """Bosch HVAC User Interface cluster"""
+
+    ScreenOrientation: Final = ScreenOrientation
+    DisplayMode: Final = DisplayMode
+    ScreenTimeout: Final = ScreenTimeout
+    ScreenBrightness: Final = ScreenBrightness
+
+    class AttributeDefs(UserInterface.AttributeDefs):
+        screen_orientation: Final = ZCLAttributeDef(
+            id=SCREEN_ORIENTATION,
+            type=ScreenOrientation,
+            access="rw",
+            is_manufacturer_specific=True
+        )
+        display_mode: Final = ZCLAttributeDef(
+            id=DISPLAY_MODE,
+            type=DisplayMode,
+            access="rw",
+            is_manufacturer_specific=True
+        )
+        screen_timeout: Final = ZCLAttributeDef(
+            id=SCREEN_TIMEOUT,
+            type=ScreenTimeout,
+            access="rw",
+            is_manufacturer_specific=True
+        )
+        screen_brightness: Final = ZCLAttributeDef(
+            id=SCREEN_BRIGHTNESS,
+            type=ScreenBrightness,
+            access="rw",
+            is_manufacturer_specific=True
+        )
+
+
+class BoschThermostat(Thermostat):
+    """Bosch Thermostat cluster"""
+
+    WindowOpen: Final = WindowOpen
+
+    class AttributeDefs(Thermostat.AttributeDefs):
+        window_open: Final = ZCLAttributeDef(
+            id=WINDOW_OPEN,
+            type=WindowOpen,
+            access="rw",
+            is_manufacturer_specific=True,
+        )
+
+
+class RBSHTRV0ZBEU(CustomDevice):
+    """Custom device representing Bosch Radiator Thermostat II."""
+
+    manufacturer_id_override = MANUFACTURER_ID
+
+    signature = {
+        MODELS_INFO: [(BOSCH, "RBSH-TRV0-ZB-EU")],
+        ENDPOINTS: {
+            1: {
+                PROFILE_ID: zha.PROFILE_ID,
+                DEVICE_TYPE: zha.DeviceType.THERMOSTAT,
+                INPUT_CLUSTERS: [
+                    Basic.cluster_id,
+                    PowerConfigurationCluster.cluster_id,
+                    Identify.cluster_id,
+                    Groups.cluster_id,
+                    PollControl.cluster_id,
+                    Thermostat.cluster_id,
+                    UserInterface.cluster_id,
+                    Diagnostic.cluster_id,
+                ],
+                OUTPUT_CLUSTERS: [
+                    Ota.cluster_id,
+                    Time.cluster_id
+                ],
+            }
+        },
+    }
+
+    replacement = {
+        ENDPOINTS: {
+            1: {
+                INPUT_CLUSTERS: [
+                    Basic.cluster_id,
+                    PowerConfigurationCluster.cluster_id,
+                    Identify.cluster_id,
+                    Groups.cluster_id,
+                    PollControl.cluster_id,
+                    BoschThermostat,
+                    BoschHvacUserInterface,
+                    Diagnostic.cluster_id,
+                ],
+                OUTPUT_CLUSTERS: [
+                    Ota.cluster_id,
+                    Time.cluster_id
+                ],
+            }
+        }
+    }