diff --git a/homeassistant/components/melcloud/__init__.py b/homeassistant/components/melcloud/__init__.py
index 30645661ff1..d78807106c1 100644
--- a/homeassistant/components/melcloud/__init__.py
+++ b/homeassistant/components/melcloud/__init__.py
@@ -27,9 +27,11 @@ MIN_TIME_BETWEEN_UPDATES = timedelta(minutes=15)
 
 PLATFORMS = [Platform.CLIMATE, Platform.SENSOR, Platform.WATER_HEATER]
 
+type MelCloudConfigEntry = ConfigEntry[dict[str, list[MelCloudDevice]]]
 
-async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
-    """Establish connection with MELClooud."""
+
+async def async_setup_entry(hass: HomeAssistant, entry: MelCloudConfigEntry) -> bool:
+    """Establish connection with MELCloud."""
     conf = entry.data
     try:
         mel_devices = await mel_devices_setup(hass, conf[CONF_TOKEN])
@@ -40,20 +42,14 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     except (TimeoutError, ClientConnectionError) as ex:
         raise ConfigEntryNotReady from ex
 
-    hass.data.setdefault(DOMAIN, {}).update({entry.entry_id: mel_devices})
+    entry.runtime_data = mel_devices
     await hass.config_entries.async_forward_entry_setups(entry, PLATFORMS)
     return True
 
 
 async def async_unload_entry(hass: HomeAssistant, config_entry: ConfigEntry) -> bool:
     """Unload a config entry."""
-    unload_ok = await hass.config_entries.async_unload_platforms(
-        config_entry, PLATFORMS
-    )
-    hass.data[DOMAIN].pop(config_entry.entry_id)
-    if not hass.data[DOMAIN]:
-        hass.data.pop(DOMAIN)
-    return unload_ok
+    return await hass.config_entries.async_unload_platforms(config_entry, PLATFORMS)
 
 
 class MelCloudDevice:
diff --git a/homeassistant/components/melcloud/climate.py b/homeassistant/components/melcloud/climate.py
index 19c333e5825..b5fd57c716d 100644
--- a/homeassistant/components/melcloud/climate.py
+++ b/homeassistant/components/melcloud/climate.py
@@ -24,13 +24,12 @@ from homeassistant.components.climate import (
     HVACAction,
     HVACMode,
 )
-from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import ATTR_TEMPERATURE, UnitOfTemperature
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers import config_validation as cv, entity_platform
 from homeassistant.helpers.entity_platform import AddConfigEntryEntitiesCallback
 
-from . import MelCloudDevice
+from . import MelCloudConfigEntry, MelCloudDevice
 from .const import (
     ATTR_STATUS,
     ATTR_VANE_HORIZONTAL,
@@ -38,7 +37,6 @@ from .const import (
     ATTR_VANE_VERTICAL,
     ATTR_VANE_VERTICAL_POSITIONS,
     CONF_POSITION,
-    DOMAIN,
     SERVICE_SET_VANE_HORIZONTAL,
     SERVICE_SET_VANE_VERTICAL,
 )
@@ -77,11 +75,11 @@ ATW_ZONE_HVAC_ACTION_LOOKUP = {
 
 async def async_setup_entry(
     hass: HomeAssistant,
-    entry: ConfigEntry,
+    entry: MelCloudConfigEntry,
     async_add_entities: AddConfigEntryEntitiesCallback,
 ) -> None:
     """Set up MelCloud device climate based on config_entry."""
-    mel_devices = hass.data[DOMAIN][entry.entry_id]
+    mel_devices = entry.runtime_data
     entities: list[AtaDeviceClimate | AtwDeviceZoneClimate] = [
         AtaDeviceClimate(mel_device, mel_device.device)
         for mel_device in mel_devices[DEVICE_TYPE_ATA]
diff --git a/homeassistant/components/melcloud/diagnostics.py b/homeassistant/components/melcloud/diagnostics.py
index 31e52bf2bde..4606b7c25e5 100644
--- a/homeassistant/components/melcloud/diagnostics.py
+++ b/homeassistant/components/melcloud/diagnostics.py
@@ -5,11 +5,12 @@ from __future__ import annotations
 from typing import Any
 
 from homeassistant.components.diagnostics import async_redact_data
-from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import CONF_TOKEN, CONF_USERNAME
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers import entity_registry as er
 
+from . import MelCloudConfigEntry
+
 TO_REDACT = {
     CONF_USERNAME,
     CONF_TOKEN,
@@ -17,7 +18,7 @@ TO_REDACT = {
 
 
 async def async_get_config_entry_diagnostics(
-    hass: HomeAssistant, entry: ConfigEntry
+    hass: HomeAssistant, entry: MelCloudConfigEntry
 ) -> dict[str, Any]:
     """Return diagnostics for the config entry."""
     ent_reg = er.async_get(hass)
diff --git a/homeassistant/components/melcloud/sensor.py b/homeassistant/components/melcloud/sensor.py
index 51a026e717a..36800b2645d 100644
--- a/homeassistant/components/melcloud/sensor.py
+++ b/homeassistant/components/melcloud/sensor.py
@@ -15,13 +15,11 @@ from homeassistant.components.sensor import (
     SensorEntityDescription,
     SensorStateClass,
 )
-from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import UnitOfEnergy, UnitOfTemperature
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers.entity_platform import AddConfigEntryEntitiesCallback
 
-from . import MelCloudDevice
-from .const import DOMAIN
+from . import MelCloudConfigEntry, MelCloudDevice
 
 
 @dataclasses.dataclass(frozen=True, kw_only=True)
@@ -105,11 +103,11 @@ ATW_ZONE_SENSORS: tuple[MelcloudSensorEntityDescription, ...] = (
 
 async def async_setup_entry(
     hass: HomeAssistant,
-    entry: ConfigEntry,
+    entry: MelCloudConfigEntry,
     async_add_entities: AddConfigEntryEntitiesCallback,
 ) -> None:
     """Set up MELCloud device sensors based on config_entry."""
-    mel_devices = hass.data[DOMAIN].get(entry.entry_id)
+    mel_devices = entry.runtime_data
 
     entities: list[MelDeviceSensor] = [
         MelDeviceSensor(mel_device, description)
diff --git a/homeassistant/components/melcloud/water_heater.py b/homeassistant/components/melcloud/water_heater.py
index 76fbad41575..f006df2478e 100644
--- a/homeassistant/components/melcloud/water_heater.py
+++ b/homeassistant/components/melcloud/water_heater.py
@@ -17,22 +17,21 @@ from homeassistant.components.water_heater import (
     WaterHeaterEntity,
     WaterHeaterEntityFeature,
 )
-from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import UnitOfTemperature
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers.entity_platform import AddConfigEntryEntitiesCallback
 
-from . import DOMAIN, MelCloudDevice
+from . import MelCloudConfigEntry, MelCloudDevice
 from .const import ATTR_STATUS
 
 
 async def async_setup_entry(
     hass: HomeAssistant,
-    entry: ConfigEntry,
+    entry: MelCloudConfigEntry,
     async_add_entities: AddConfigEntryEntitiesCallback,
 ) -> None:
     """Set up MelCloud device climate based on config_entry."""
-    mel_devices = hass.data[DOMAIN][entry.entry_id]
+    mel_devices = entry.runtime_data
     async_add_entities(
         [
             AtwWaterHeater(mel_device, mel_device.device)