diff --git a/homeassistant/components/melnor/__init__.py b/homeassistant/components/melnor/__init__.py
index 4cc112509d99..312a28b562ae 100644
--- a/homeassistant/components/melnor/__init__.py
+++ b/homeassistant/components/melnor/__init__.py
@@ -7,7 +7,10 @@ from homeassistant.components.bluetooth.match import BluetoothCallbackMatcher
 from homeassistant.const import CONF_ADDRESS, Platform
 from homeassistant.core import HomeAssistant, callback
 from homeassistant.exceptions import ConfigEntryNotReady
+from homeassistant.helpers import device_registry as dr
+from homeassistant.helpers.device_registry import CONNECTION_BLUETOOTH
 
+from .const import DOMAIN
 from .coordinator import MelnorConfigEntry, MelnorDataUpdateCoordinator
 
 PLATFORMS: list[Platform] = [
@@ -54,6 +57,18 @@ async def async_setup_entry(hass: HomeAssistant, entry: MelnorConfigEntry) -> bo
     await coordinator.async_config_entry_first_refresh()
 
     entry.runtime_data = coordinator
+
+    # Register the parent device up front so zone entities can deterministically
+    # resolve its via_device_id, regardless of platform setup order.
+    dr.async_get(hass).async_get_or_create(
+        config_entry_id=entry.entry_id,
+        identifiers={(DOMAIN, device.mac)},
+        connections={(CONNECTION_BLUETOOTH, device.mac)},
+        manufacturer="Melnor",
+        model=device.model,
+        name=device.name,
+    )
+
     await hass.config_entries.async_forward_entry_setups(entry, PLATFORMS)
 
     return True
diff --git a/homeassistant/components/melnor/entity.py b/homeassistant/components/melnor/entity.py
index 35e804111f48..ac85df205c85 100644
--- a/homeassistant/components/melnor/entity.py
+++ b/homeassistant/components/melnor/entity.py
@@ -7,6 +7,7 @@ from melnor_bluetooth.device import Device, Valve
 
 from homeassistant.components.number import EntityDescription
 from homeassistant.core import callback
+from homeassistant.helpers import device_registry as dr
 from homeassistant.helpers.device_registry import CONNECTION_BLUETOOTH, DeviceInfo
 from homeassistant.helpers.update_coordinator import CoordinatorEntity
 
@@ -76,7 +77,11 @@ class MelnorZoneEntity(MelnorBluetoothEntity):
             identifiers={(DOMAIN, f"{self._device.mac}-zone{self._valve.id}")},
             manufacturer="Melnor",
             name=f"Zone {valve.id + 1}",
-            via_device=(DOMAIN, self._device.mac),
+            via_device_id=dr.async_get_device_id_by_identifier(
+                coordinator.hass,
+                (DOMAIN, self._device.mac),
+                config_entry_id=coordinator.config_entry.entry_id,
+            ),
         )
 
 
diff --git a/tests/components/melnor/test_init.py b/tests/components/melnor/test_init.py
index 229d1b3cc337..6af51b4dbde8 100644
--- a/tests/components/melnor/test_init.py
+++ b/tests/components/melnor/test_init.py
@@ -35,3 +35,29 @@ async def test_device_registry(
         identifiers={(DOMAIN, FAKE_ADDRESS_1)}
     )
     assert device_entry == snapshot
+
+
+async def test_zone_device_via_device(
+    hass: HomeAssistant,
+    device_registry: dr.DeviceRegistry,
+) -> None:
+    """Test that zone devices link to the parent device via via_device_id."""
+    entry = mock_config_entry(hass)
+
+    with (
+        patch_async_ble_device_from_address(),
+        patch_melnor_device(),
+        patch_async_register_callback(),
+    ):
+        assert await hass.config_entries.async_setup(entry.entry_id)
+
+    parent_device = device_registry.async_get_device_by_identifier(
+        (DOMAIN, FAKE_ADDRESS_1), entry.entry_id
+    )
+    zone_device = device_registry.async_get_device_by_identifier(
+        (DOMAIN, f"{FAKE_ADDRESS_1}-zone0"), entry.entry_id
+    )
+
+    assert parent_device is not None
+    assert zone_device is not None
+    assert zone_device.via_device_id == parent_device.id