diff --git a/homeassistant/components/rainbird/calendar.py b/homeassistant/components/rainbird/calendar.py
index 356f7d7cc4e..2001a14ac93 100644
--- a/homeassistant/components/rainbird/calendar.py
+++ b/homeassistant/components/rainbird/calendar.py
@@ -61,7 +61,7 @@ class RainBirdCalendarEntity(
         """Create the Calendar event device."""
         super().__init__(coordinator)
         self._event: CalendarEvent | None = None
-        if unique_id:
+        if unique_id is not None:
             self._attr_unique_id = unique_id
             self._attr_device_info = device_info
         else:
diff --git a/homeassistant/components/rainbird/number.py b/homeassistant/components/rainbird/number.py
index 1e72fabafcd..dd9664222b2 100644
--- a/homeassistant/components/rainbird/number.py
+++ b/homeassistant/components/rainbird/number.py
@@ -51,7 +51,7 @@ class RainDelayNumber(CoordinatorEntity[RainbirdUpdateCoordinator], NumberEntity
     ) -> None:
         """Initialize the Rain Bird sensor."""
         super().__init__(coordinator)
-        if coordinator.unique_id:
+        if coordinator.unique_id is not None:
             self._attr_unique_id = f"{coordinator.unique_id}-rain-delay"
             self._attr_device_info = coordinator.device_info
         else:
diff --git a/homeassistant/components/rainbird/sensor.py b/homeassistant/components/rainbird/sensor.py
index d44e7156cb5..84bf8cadb7b 100644
--- a/homeassistant/components/rainbird/sensor.py
+++ b/homeassistant/components/rainbird/sensor.py
@@ -52,7 +52,7 @@ class RainBirdSensor(CoordinatorEntity[RainbirdUpdateCoordinator], SensorEntity)
         """Initialize the Rain Bird sensor."""
         super().__init__(coordinator)
         self.entity_description = description
-        if coordinator.unique_id:
+        if coordinator.unique_id is not None:
             self._attr_unique_id = f"{coordinator.unique_id}-{description.key}"
             self._attr_device_info = coordinator.device_info
         else:
diff --git a/homeassistant/components/rainbird/switch.py b/homeassistant/components/rainbird/switch.py
index 62b3b0e9a8c..da3979a27fd 100644
--- a/homeassistant/components/rainbird/switch.py
+++ b/homeassistant/components/rainbird/switch.py
@@ -65,17 +65,18 @@ class RainBirdSwitch(CoordinatorEntity[RainbirdUpdateCoordinator], SwitchEntity)
         """Initialize a Rain Bird Switch Device."""
         super().__init__(coordinator)
         self._zone = zone
-        if coordinator.unique_id:
+        _LOGGER.debug("coordinator.unique_id=%s", coordinator.unique_id)
+        if coordinator.unique_id is not None:
             self._attr_unique_id = f"{coordinator.unique_id}-{zone}"
         device_name = f"{MANUFACTURER} Sprinkler {zone}"
         if imported_name:
             self._attr_name = imported_name
             self._attr_has_entity_name = False
         else:
-            self._attr_name = None if coordinator.unique_id else device_name
+            self._attr_name = None if coordinator.unique_id is not None else device_name
             self._attr_has_entity_name = True
         self._duration_minutes = duration_minutes
-        if coordinator.unique_id and self._attr_unique_id:
+        if coordinator.unique_id is not None and self._attr_unique_id is not None:
             self._attr_device_info = DeviceInfo(
                 name=device_name,
                 identifiers={(DOMAIN, self._attr_unique_id)},
diff --git a/tests/components/rainbird/test_switch.py b/tests/components/rainbird/test_switch.py
index 46a875e8928..31b64dded99 100644
--- a/tests/components/rainbird/test_switch.py
+++ b/tests/components/rainbird/test_switch.py
@@ -17,6 +17,7 @@ from .conftest import (
     PASSWORD,
     RAIN_DELAY_OFF,
     RAIN_SENSOR_OFF,
+    SERIAL_NUMBER,
     ZONE_3_ON_RESPONSE,
     ZONE_5_ON_RESPONSE,
     ZONE_OFF_RESPONSE,
@@ -286,7 +287,7 @@ async def test_switch_error(
 @pytest.mark.parametrize(
     ("config_entry_unique_id"),
     [
-        None,
+        (None),
     ],
 )
 async def test_no_unique_id(
@@ -307,3 +308,34 @@ async def test_no_unique_id(
 
     entity_entry = entity_registry.async_get("switch.rain_bird_sprinkler_3")
     assert entity_entry is None
+
+
+@pytest.mark.parametrize(
+    ("config_entry_unique_id", "entity_unique_id"),
+    [
+        (SERIAL_NUMBER, "1263613994342-3"),
+        # Some existing config entries may have a "0" serial number but preserve
+        # their unique id
+        (0, "0-3"),
+    ],
+)
+async def test_has_unique_id(
+    hass: HomeAssistant,
+    setup_integration: ComponentSetup,
+    aioclient_mock: AiohttpClientMocker,
+    responses: list[AiohttpClientMockResponse],
+    entity_registry: er.EntityRegistry,
+    entity_unique_id: str,
+) -> None:
+    """Test an irrigation switch with no unique id."""
+
+    assert await setup_integration()
+
+    zone = hass.states.get("switch.rain_bird_sprinkler_3")
+    assert zone is not None
+    assert zone.attributes.get("friendly_name") == "Rain Bird Sprinkler 3"
+    assert zone.state == "off"
+
+    entity_entry = entity_registry.async_get("switch.rain_bird_sprinkler_3")
+    assert entity_entry
+    assert entity_entry.unique_id == entity_unique_id