diff --git a/homeassistant/components/weheat/diagnostics.py b/homeassistant/components/weheat/diagnostics.py
new file mode 100644
index 000000000000..ea119c86bae2
--- /dev/null
+++ b/homeassistant/components/weheat/diagnostics.py
@@ -0,0 +1,30 @@
+"""Diagnostics support for Weheat."""
+
+from typing import Any
+
+from homeassistant.components.diagnostics import async_redact_data
+from homeassistant.core import HomeAssistant
+
+from .coordinator import WeheatConfigEntry
+
+TO_REDACT = {"heat_pump_id", "uuid", "sn"}
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, entry: WeheatConfigEntry
+) -> dict[str, Any]:
+    """Return diagnostics for a config entry."""
+    return {
+        "heat_pumps": [
+            {
+                "info": async_redact_data(vars(weheatdata.heat_pump_info), TO_REDACT),
+                "logs": async_redact_data(
+                    weheatdata.data_coordinator.data.raw_content or {}, TO_REDACT
+                ),
+                "energy": async_redact_data(
+                    weheatdata.energy_coordinator.data.raw_content or {}, TO_REDACT
+                ),
+            }
+            for weheatdata in entry.runtime_data
+        ]
+    }
diff --git a/homeassistant/components/weheat/quality_scale.yaml b/homeassistant/components/weheat/quality_scale.yaml
index 2d4e4b892543..ad4bfee02cbd 100644
--- a/homeassistant/components/weheat/quality_scale.yaml
+++ b/homeassistant/components/weheat/quality_scale.yaml
@@ -54,7 +54,7 @@ rules:
 
   # Gold
   devices: done
-  diagnostics: todo
+  diagnostics: done
   discovery-update-info:
     status: exempt
     comment: |
diff --git a/tests/components/weheat/conftest.py b/tests/components/weheat/conftest.py
index a7dc38f3c593..93aea72c3e5a 100644
--- a/tests/components/weheat/conftest.py
+++ b/tests/components/weheat/conftest.py
@@ -140,6 +140,11 @@ def mock_weheat_heat_pump_instance() -> MagicMock:
     mock_heat_pump_instance.indoor_unit_dhw_valve_or_pump_state = None
     mock_heat_pump_instance.indoor_unit_gas_boiler_state = False
     mock_heat_pump_instance.indoor_unit_electric_heater_state = True
+    mock_heat_pump_instance.raw_content = {
+        "heat_pump_id": TEST_HP_UUID,
+        "t_water_in": 11,
+        "total_ein_heating": 12345,
+    }
 
     return mock_heat_pump_instance
 
diff --git a/tests/components/weheat/snapshots/test_diagnostics.ambr b/tests/components/weheat/snapshots/test_diagnostics.ambr
new file mode 100644
index 000000000000..6db4e23f0e93
--- /dev/null
+++ b/tests/components/weheat/snapshots/test_diagnostics.ambr
@@ -0,0 +1,27 @@
+# serializer version: 1
+# name: test_diagnostics
+  dict({
+    'heat_pumps': list([
+      dict({
+        'energy': dict({
+          'heat_pump_id': '**REDACTED**',
+          't_water_in': 11,
+          'total_ein_heating': 12345,
+        }),
+        'info': dict({
+          'device_name': None,
+          'has_ch_boiler': False,
+          'has_dhw': True,
+          'model': 'Test Model',
+          'sn': '**REDACTED**',
+          'uuid': '**REDACTED**',
+        }),
+        'logs': dict({
+          'heat_pump_id': '**REDACTED**',
+          't_water_in': 11,
+          'total_ein_heating': 12345,
+        }),
+      }),
+    ]),
+  })
+# ---
diff --git a/tests/components/weheat/test_diagnostics.py b/tests/components/weheat/test_diagnostics.py
new file mode 100644
index 000000000000..ed4868af9738
--- /dev/null
+++ b/tests/components/weheat/test_diagnostics.py
@@ -0,0 +1,50 @@
+"""Tests for the weheat diagnostics."""
+
+from unittest.mock import AsyncMock
+
+import pytest
+from syrupy.assertion import SnapshotAssertion
+
+from homeassistant.core import HomeAssistant
+
+from . import setup_integration
+
+from tests.common import MockConfigEntry
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+from tests.typing import ClientSessionGenerator
+
+
+@pytest.mark.usefixtures("mock_weheat_discover", "mock_weheat_heat_pump")
+async def test_diagnostics(
+    hass: HomeAssistant,
+    hass_client: ClientSessionGenerator,
+    mock_config_entry: MockConfigEntry,
+    snapshot: SnapshotAssertion,
+) -> None:
+    """Test the diagnostics of a config entry."""
+    await setup_integration(hass, mock_config_entry)
+
+    assert (
+        await get_diagnostics_for_config_entry(hass, hass_client, mock_config_entry)
+        == snapshot
+    )
+
+
+@pytest.mark.usefixtures("mock_weheat_discover")
+async def test_diagnostics_without_data(
+    hass: HomeAssistant,
+    hass_client: ClientSessionGenerator,
+    mock_config_entry: MockConfigEntry,
+    mock_weheat_heat_pump: AsyncMock,
+) -> None:
+    """Test the diagnostics of a heat pump that reported nothing yet."""
+    mock_weheat_heat_pump.raw_content = None
+
+    await setup_integration(hass, mock_config_entry)
+
+    diagnostics = await get_diagnostics_for_config_entry(
+        hass, hass_client, mock_config_entry
+    )
+
+    assert diagnostics["heat_pumps"][0]["logs"] == {}
+    assert diagnostics["heat_pumps"][0]["energy"] == {}