diff --git a/tests/test_systemmanager.py b/tests/test_systemmanager.py
index 6a4f149..b46169a 100644
--- a/tests/test_systemmanager.py
+++ b/tests/test_systemmanager.py
@@ -82,6 +82,19 @@ def test_set_hot_water_setpoint_temperature(self):
         self.assertTrue(self.manager.set_hot_water_setpoint_temperature(hotwater, 60))
         self.assertEqual(json.dumps(payload), responses.calls[-1].request.body.decode('utf-8'))
 
+    @responses.activate
+    def test_set_hot_water_setpoint_temperature_number_to_round(self):
+        serial = TestUtil.mock_full_auth_success()
+
+        hotwater = HotWater('id', 'name', None, 50, 55, HeatingMode.AUTO)
+        url = Urls.hot_water_temperature_setpoint(hotwater.id)
+        payload = Payloads.hotwater_temperature_setpoint(60.5)
+
+        responses.add(responses.PUT, url.format(serial_number=serial), status=200)
+
+        self.assertTrue(self.manager.set_hot_water_setpoint_temperature(hotwater, 60.4))
+        self.assertEqual(json.dumps(payload), responses.calls[-1].request.body.decode('utf-8'))
+
     @responses.activate
     def test_set_quick_mode_no_current_quick_mode(self):
         serial = TestUtil.mock_full_auth_success()
diff --git a/vr900connector/systemmanager.py b/vr900connector/systemmanager.py
index 9c0c6a4..8eb22db 100644
--- a/vr900connector/systemmanager.py
+++ b/vr900connector/systemmanager.py
@@ -78,7 +78,7 @@ def set_hot_water_setpoint_temperature(self, hot_water: HotWater, temperature: f
         LOGGER.info("Will try to set dhw target temperature to %s", temperature)
         if temperature and hot_water:
             self._connector.put(Urls.hot_water_temperature_setpoint(hot_water.id),
-                                Payloads.hotwater_temperature_setpoint(round(float(temperature), 1)))
+                                Payloads.hotwater_temperature_setpoint(self._round(temperature)))
             return True
         else:
             LOGGER.debug("No temperature nor hot_water provided, nothing to do")
@@ -215,7 +215,7 @@ def set_room_setpoint_temperature(self, room: Room, temperature: float):
         LOGGER.info("Will try to set room target temperature to %s", temperature)
         if temperature and room:
             self._connector.put(Urls.room_set_temperature_setpoint(room.id),
-                                Payloads.room_temperature_setpoint(round(float(temperature), 1)))
+                                Payloads.room_temperature_setpoint(self._round(temperature)))
             return True
         else:
             LOGGER.debug("No temperature nor room provided, nothing to do")
@@ -232,7 +232,7 @@ def set_zone_setpoint_temperature(self, zone: Zone, temperature: float):
         LOGGER.info("Will try to set zone target temperature to %s", temperature)
         if temperature and zone:
             self._connector.put(Urls.zone_heating_setpoint_temperature(zone.id),
-                                Payloads.zone_temperature_setpoint(round(float(temperature), 1)))
+                                Payloads.zone_temperature_setpoint(self._round(temperature)))
             return True
         else:
             LOGGER.debug("No temperature nor zone provided, nothing to do")
@@ -249,7 +249,7 @@ def set_zone_setback_temperature(self, zone: Zone, temperature: float):
         LOGGER.info("Will try to set zone setback temperature to %s", temperature)
         if temperature and zone:
             self._connector.put(Urls.zone_heating_setback_temperature(zone.id),
-                                Payloads.zone_temperature_setback(round(float(temperature), 1)))
+                                Payloads.zone_temperature_setback(self._round(temperature)))
             return True
         else:
             LOGGER.debug("No temperature nor zone provided, nothing to do")
@@ -294,3 +294,11 @@ def logout(self):
         Get logged out from the API
         """
         self._connector.logout()
+
+    def _round(self, number: float):
+        """
+        This function round a float to the nearest 0.5, as vaillant API only accepts 0.5 step
+        :param number: the number to round
+        :return: the rounded number
+        """
+        return round(number * 2) / 2