diff --git a/homeassistant/components/thermostat/honeywell.py b/homeassistant/components/thermostat/honeywell.py
index ab583d3ded0..4139c5d8aa7 100644
--- a/homeassistant/components/thermostat/honeywell.py
+++ b/homeassistant/components/thermostat/honeywell.py
@@ -73,7 +73,7 @@ class RoundThermostat(ThermostatDevice):
     def target_temperature(self):
         """ Returns the temperature we try to reach. """
         if self._is_dhw:
-            raise NotImplementedError
+            return None
         return self._target_temperature
 
     def set_temperature(self, temperature):