diff --git a/tests/components/greeneye_monitor/common.py b/tests/components/greeneye_monitor/common.py
index 952992ee500..0a19b79795f 100644
--- a/tests/components/greeneye_monitor/common.py
+++ b/tests/components/greeneye_monitor/common.py
@@ -128,6 +128,35 @@ SINGLE_MONITOR_CONFIG_VOLTAGE_SENSORS = make_single_monitor_config_with_sensors(
     }
 )
 
+MULTI_MONITOR_CONFIG = {
+    DOMAIN: {
+        CONF_PORT: 7513,
+        CONF_MONITORS: [
+            {
+                CONF_SERIAL_NUMBER: "00000001",
+                CONF_TEMPERATURE_SENSORS: {
+                    CONF_TEMPERATURE_UNIT: "C",
+                    CONF_SENSORS: [{CONF_NUMBER: 1, CONF_NAME: "unit_1_temp_1"}],
+                },
+            },
+            {
+                CONF_SERIAL_NUMBER: "00000002",
+                CONF_TEMPERATURE_SENSORS: {
+                    CONF_TEMPERATURE_UNIT: "F",
+                    CONF_SENSORS: [{CONF_NUMBER: 1, CONF_NAME: "unit_2_temp_1"}],
+                },
+            },
+            {
+                CONF_SERIAL_NUMBER: "00000003",
+                CONF_TEMPERATURE_SENSORS: {
+                    CONF_TEMPERATURE_UNIT: "C",
+                    CONF_SENSORS: [{CONF_NUMBER: 1, CONF_NAME: "unit_3_temp_1"}],
+                },
+            },
+        ],
+    }
+}
+
 
 async def setup_greeneye_monitor_component_with_config(
     hass: HomeAssistant, config: ConfigType
diff --git a/tests/components/greeneye_monitor/test_init.py b/tests/components/greeneye_monitor/test_init.py
index 5bffe2eb4a4..c8e13714939 100644
--- a/tests/components/greeneye_monitor/test_init.py
+++ b/tests/components/greeneye_monitor/test_init.py
@@ -6,23 +6,12 @@ from unittest.mock import AsyncMock
 
 import pytest
 
-from homeassistant.components.greeneye_monitor import (
-    CONF_MONITORS,
-    CONF_NUMBER,
-    CONF_SERIAL_NUMBER,
-    CONF_TEMPERATURE_SENSORS,
-    DOMAIN,
-)
-from homeassistant.const import (
-    CONF_NAME,
-    CONF_PORT,
-    CONF_SENSORS,
-    CONF_TEMPERATURE_UNIT,
-)
+from homeassistant.components.greeneye_monitor import DOMAIN
 from homeassistant.core import HomeAssistant
 from homeassistant.setup import async_setup_component
 
 from .common import (
+    MULTI_MONITOR_CONFIG,
     SINGLE_MONITOR_CONFIG_NO_SENSORS,
     SINGLE_MONITOR_CONFIG_POWER_SENSORS,
     SINGLE_MONITOR_CONFIG_PULSE_COUNTERS,
@@ -155,35 +144,12 @@ async def test_multi_monitor_config(hass: HomeAssistant, monitors: AsyncMock) ->
     """Test that component setup registers entities from multiple monitors correctly."""
     assert await setup_greeneye_monitor_component_with_config(
         hass,
-        {
-            DOMAIN: {
-                CONF_PORT: 7513,
-                CONF_MONITORS: [
-                    {
-                        CONF_SERIAL_NUMBER: "00000001",
-                        CONF_TEMPERATURE_SENSORS: {
-                            CONF_TEMPERATURE_UNIT: "C",
-                            CONF_SENSORS: [
-                                {CONF_NUMBER: 1, CONF_NAME: "unit_1_temp_1"}
-                            ],
-                        },
-                    },
-                    {
-                        CONF_SERIAL_NUMBER: "00000002",
-                        CONF_TEMPERATURE_SENSORS: {
-                            CONF_TEMPERATURE_UNIT: "F",
-                            CONF_SENSORS: [
-                                {CONF_NUMBER: 1, CONF_NAME: "unit_2_temp_1"}
-                            ],
-                        },
-                    },
-                ],
-            }
-        },
+        MULTI_MONITOR_CONFIG,
     )
 
     assert_temperature_sensor_registered(hass, 1, 1, "unit_1_temp_1")
     assert_temperature_sensor_registered(hass, 2, 1, "unit_2_temp_1")
+    assert_temperature_sensor_registered(hass, 3, 1, "unit_3_temp_1")
 
 
 async def test_setup_and_shutdown(hass: HomeAssistant, monitors: AsyncMock) -> None:
diff --git a/tests/components/greeneye_monitor/test_sensor.py b/tests/components/greeneye_monitor/test_sensor.py
index 9cd6f97fc38..ac1fe92873a 100644
--- a/tests/components/greeneye_monitor/test_sensor.py
+++ b/tests/components/greeneye_monitor/test_sensor.py
@@ -13,6 +13,7 @@ from homeassistant.helpers.entity_registry import (
 )
 
 from .common import (
+    MULTI_MONITOR_CONFIG,
     SINGLE_MONITOR_CONFIG_POWER_SENSORS,
     SINGLE_MONITOR_CONFIG_PULSE_COUNTERS,
     SINGLE_MONITOR_CONFIG_TEMPERATURE_SENSORS,
@@ -154,6 +155,17 @@ async def test_voltage_sensor(hass: HomeAssistant, monitors: AsyncMock) -> None:
     assert_sensor_state(hass, "sensor.voltage_1", "120.0")
 
 
+async def test_multi_monitor_sensors(hass: HomeAssistant, monitors: AsyncMock) -> None:
+    """Test that sensors still work when multiple monitors are registered."""
+    await setup_greeneye_monitor_component_with_config(hass, MULTI_MONITOR_CONFIG)
+    connect_monitor(monitors, 1)
+    connect_monitor(monitors, 2)
+    connect_monitor(monitors, 3)
+    assert_sensor_state(hass, "sensor.unit_1_temp_1", "32.0")
+    assert_sensor_state(hass, "sensor.unit_2_temp_1", "0.0")
+    assert_sensor_state(hass, "sensor.unit_3_temp_1", "32.0")
+
+
 def connect_monitor(monitors: AsyncMock, serial_number: int) -> MagicMock:
     """Simulate a monitor connecting to Home Assistant. Returns the mock monitor API object."""
     monitor = mock_monitor(serial_number)