diff --git a/homeassistant/components/neopool/config_flow.py b/homeassistant/components/neopool/config_flow.py
index b6fde0365d2cd9..debe7f4c16ee56 100644
--- a/homeassistant/components/neopool/config_flow.py
+++ b/homeassistant/components/neopool/config_flow.py
@@ -20,6 +20,8 @@
 from homeassistant.core import callback
 
 from .const import (
+    CONF_MODBUS_FRAMER,
+    CONF_UNIT_ID,
     CONF_USE_AUX1,
     CONF_USE_AUX2,
     CONF_USE_AUX3,
@@ -40,8 +42,8 @@ async def _async_probe(user_input: dict[str, Any]) -> tuple[str | None, str | No
         serial = await async_probe_serial(
             user_input[CONF_HOST],
             port=user_input[CONF_PORT],
-            unit_id=user_input["unit_id"],
-            framer=user_input["modbus_framer"],
+            unit_id=user_input[CONF_UNIT_ID],
+            framer=user_input[CONF_MODBUS_FRAMER],
         )
     except NeoPoolConnectionError, NeoPoolTimeoutError:
         return None, "cannot_connect"
@@ -73,9 +75,9 @@ async def async_step_user(
             {
                 vol.Required(CONF_HOST): str,
                 vol.Optional(CONF_PORT, default=DEFAULT_PORT): vol.Coerce(int),
-                vol.Optional("unit_id", default=DEFAULT_UNIT_ID): vol.Coerce(int),
+                vol.Optional(CONF_UNIT_ID, default=DEFAULT_UNIT_ID): vol.Coerce(int),
                 vol.Optional(
-                    "modbus_framer",
+                    CONF_MODBUS_FRAMER,
                     default=DEFAULT_MODBUS_FRAMER,
                 ): vol.In(("tcp", "rtu")),
             }
@@ -100,6 +102,49 @@ async def async_step_user(
             errors=errors,
         )
 
+    async def async_step_reconfigure(
+        self, user_input: dict[str, Any] | None = None
+    ) -> ConfigFlowResult:
+        """Handle reconfiguration of an existing entry."""
+        entry = self._get_reconfigure_entry()
+        current = entry.data
+
+        data_schema = vol.Schema(
+            {
+                vol.Required(CONF_HOST, default=current[CONF_HOST]): str,
+                vol.Optional(
+                    CONF_PORT, default=current.get(CONF_PORT, DEFAULT_PORT)
+                ): vol.Coerce(int),
+                vol.Optional(
+                    CONF_UNIT_ID,
+                    default=current.get(CONF_UNIT_ID, DEFAULT_UNIT_ID),
+                ): vol.Coerce(int),
+                vol.Optional(
+                    CONF_MODBUS_FRAMER,
+                    default=current.get(CONF_MODBUS_FRAMER, DEFAULT_MODBUS_FRAMER),
+                ): vol.In(("tcp", "rtu")),
+            }
+        )
+
+        errors: dict[str, str] = {}
+        if user_input is not None:
+            merged = {**current, **user_input}
+            serial, error_key = await _async_probe(merged)
+            if error_key:
+                errors[CONF_HOST] = error_key
+            else:
+                await self.async_set_unique_id(serial)
+                self._abort_if_unique_id_mismatch(reason="serial_mismatch")
+                return self.async_update_reload_and_abort(entry, data=merged)
+
+        return self.async_show_form(
+            step_id="reconfigure",
+            data_schema=self.add_suggested_values_to_schema(
+                data_schema, user_input or current
+            ),
+            errors=errors,
+        )
+
 
 class NeoPoolOptionsFlowHandler(OptionsFlowWithReload):
     """Handle options flow for NeoPool integration."""
diff --git a/homeassistant/components/neopool/const.py b/homeassistant/components/neopool/const.py
index 06ff396c25ed56..33ab63a75ae95a 100644
--- a/homeassistant/components/neopool/const.py
+++ b/homeassistant/components/neopool/const.py
@@ -17,7 +17,9 @@
 DEFAULT_PORT = 502
 DEFAULT_UNIT_ID = 1
 
-# Options-flow keys.
+CONF_UNIT_ID = "unit_id"
+CONF_MODBUS_FRAMER = "modbus_framer"
+
 CONF_USE_LIGHT = "use_light"
 CONF_USE_COVER_SENSOR = "use_cover_sensor"
 CONF_USE_AUX1 = "use_aux1"
diff --git a/homeassistant/components/neopool/quality_scale.yaml b/homeassistant/components/neopool/quality_scale.yaml
index e4bcbfcd433dcb..ef1369394a49f9 100644
--- a/homeassistant/components/neopool/quality_scale.yaml
+++ b/homeassistant/components/neopool/quality_scale.yaml
@@ -80,7 +80,7 @@ rules:
   entity-translations: done
   exception-translations: done
   icon-translations: done
-  reconfiguration-flow: todo
+  reconfiguration-flow: done
   repair-issues: done
   stale-devices:
     status: exempt
diff --git a/homeassistant/components/neopool/strings.json b/homeassistant/components/neopool/strings.json
index ea8a9192b5e23e..5980ee3e2410d2 100644
--- a/homeassistant/components/neopool/strings.json
+++ b/homeassistant/components/neopool/strings.json
@@ -1,13 +1,31 @@
 {
   "config": {
     "abort": {
-      "already_configured": "[%key:common::config_flow::abort::already_configured_device%]"
+      "already_configured": "[%key:common::config_flow::abort::already_configured_device%]",
+      "reconfigure_successful": "[%key:common::config_flow::abort::reconfigure_successful%]",
+      "serial_mismatch": "The device at this address has a different serial number than the one originally configured."
     },
     "error": {
       "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]",
       "cannot_read_modbus": "Connected, but cannot read from the Modbus device. Check unit ID and framer settings."
     },
     "step": {
+      "reconfigure": {
+        "data": {
+          "host": "[%key:common::config_flow::data::host%]",
+          "modbus_framer": "[%key:component::neopool::config::step::user::data::modbus_framer%]",
+          "port": "[%key:common::config_flow::data::port%]",
+          "unit_id": "[%key:component::neopool::config::step::user::data::unit_id%]"
+        },
+        "data_description": {
+          "host": "[%key:component::neopool::config::step::user::data_description::host%]",
+          "modbus_framer": "[%key:component::neopool::config::step::user::data_description::modbus_framer%]",
+          "port": "[%key:component::neopool::config::step::user::data_description::port%]",
+          "unit_id": "[%key:component::neopool::config::step::user::data_description::unit_id%]"
+        },
+        "description": "Update the connection settings for your NeoPool controller.",
+        "title": "Reconfigure NeoPool Connection"
+      },
       "user": {
         "data": {
           "host": "[%key:common::config_flow::data::host%]",
diff --git a/tests/components/neopool/test_config_flow.py b/tests/components/neopool/test_config_flow.py
index e47240eaae6bf8..9f6923eb490974 100644
--- a/tests/components/neopool/test_config_flow.py
+++ b/tests/components/neopool/test_config_flow.py
@@ -111,6 +111,86 @@ async def test_user_flow_already_configured(
     assert result["reason"] == "already_configured"
 
 
+@pytest.mark.usefixtures("mock_neopool_client")
+async def test_reconfigure_flow(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_setup_entry: AsyncMock,
+) -> None:
+    """A reconfigure flow updates the connection settings and reloads the entry."""
+    mock_config_entry.add_to_hass(hass)
+
+    result = await mock_config_entry.start_reconfigure_flow(hass)
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "reconfigure"
+
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {**USER_INPUT, CONF_HOST: "192.0.2.50", CONF_PORT: 1502},
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "reconfigure_successful"
+    assert mock_config_entry.data[CONF_HOST] == "192.0.2.50"
+    assert mock_config_entry.data[CONF_PORT] == 1502
+
+
+@pytest.mark.parametrize(
+    ("exc_cls", "error_key"),
+    [
+        (NeoPoolConnectionError, "cannot_connect"),
+        (NeoPoolTimeoutError, "cannot_connect"),
+        (NeoPoolModbusError, "cannot_read_modbus"),
+    ],
+)
+async def test_reconfigure_flow_probe_errors_recover(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_setup_entry: AsyncMock,
+    mock_socket_connection: AsyncMock,
+    exc_cls: type[Exception],
+    error_key: str,
+) -> None:
+    """Probe errors surface as form errors, and the flow recovers on retry."""
+    mock_config_entry.add_to_hass(hass)
+    result = await mock_config_entry.start_reconfigure_flow(hass)
+
+    mock_socket_connection.side_effect = exc_cls("boom")
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {**USER_INPUT, CONF_HOST: "192.0.2.50"},
+    )
+    assert result["type"] is FlowResultType.FORM
+    assert result["errors"] == {CONF_HOST: error_key}
+
+    mock_socket_connection.side_effect = None
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {**USER_INPUT, CONF_HOST: "192.0.2.50"},
+    )
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "reconfigure_successful"
+
+
+async def test_reconfigure_flow_serial_mismatch(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_setup_entry: AsyncMock,
+    mock_socket_connection: AsyncMock,
+) -> None:
+    """A reconfigure targeting a different physical controller is rejected."""
+    mock_config_entry.add_to_hass(hass)
+    result = await mock_config_entry.start_reconfigure_flow(hass)
+
+    mock_socket_connection.return_value = "9999999999"
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {**USER_INPUT, CONF_HOST: "192.0.2.50"},
+    )
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "serial_mismatch"
+
+
 @pytest.mark.usefixtures("mock_neopool_client")
 async def test_options_flow_show_form(
     hass: HomeAssistant,