diff --git a/homeassistant/components/history/__init__.py b/homeassistant/components/history/__init__.py
index fb037e8909d..7b07fac19a6 100644
--- a/homeassistant/components/history/__init__.py
+++ b/homeassistant/components/history/__init__.py
@@ -29,7 +29,7 @@ CONFIG_SCHEMA = vol.Schema({
     })
 }, extra=vol.ALLOW_EXTRA)
 
-SIGNIFICANT_DOMAINS = ('thermostat', 'climate')
+SIGNIFICANT_DOMAINS = ('thermostat', 'climate', 'water_heater')
 IGNORE_DOMAINS = ('zone', 'scene',)