diff --git a/homeassistant/components/climate/radiotherm.py b/homeassistant/components/climate/radiotherm.py
index f914b9b4762..f0423d32c96 100644
--- a/homeassistant/components/climate/radiotherm.py
+++ b/homeassistant/components/climate/radiotherm.py
@@ -17,7 +17,7 @@ from homeassistant.const import (
     CONF_HOST, TEMP_FAHRENHEIT, ATTR_TEMPERATURE, PRECISION_HALVES)
 import homeassistant.helpers.config_validation as cv
 
-REQUIREMENTS = ['radiotherm==1.4.1']
+REQUIREMENTS = ['radiotherm==2.0.0']
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -235,13 +235,15 @@ class RadioThermostat(ClimateDevice):
             self._name = self.device.name['raw']
 
         # Request the current state from the thermostat.
-        data = self.device.tstat['raw']
+        import radiotherm
+        try:
+            data = self.device.tstat['raw']
+        except radiotherm.validate.RadiothermTstatError:
+            _LOGGER.error('%s (%s) was busy (invalid value returned)',
+                          self._name, self.device.host)
+            return
 
         current_temp = data['temp']
-        if current_temp == -1:
-            _LOGGER.error('%s (%s) was busy (temp == -1)', self._name,
-                          self.device.host)
-            return
 
         # Map thermostat values into various STATE_ flags.
         self._current_temperature = current_temp
diff --git a/requirements_all.txt b/requirements_all.txt
index 27863a99aec..ec22bccfa9a 100644
--- a/requirements_all.txt
+++ b/requirements_all.txt
@@ -1352,7 +1352,7 @@ quantum-gateway==0.0.3
 rachiopy==0.1.3
 
 # homeassistant.components.climate.radiotherm
-radiotherm==1.4.1
+radiotherm==2.0.0
 
 # homeassistant.components.raincloud
 raincloudy==0.0.5