From b88772eea0bacea18d2a491d7ecba1303f628152 Mon Sep 17 00:00:00 2001
From: joe248 <24720046+joe248@users.noreply.github.com>
Date: Fri, 27 Sep 2019 08:31:01 -0500
Subject: [PATCH] Revert Nest HVAC mode when disabling Eco mode (#26934)

---
 homeassistant/components/nest/climate.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/homeassistant/components/nest/climate.py b/homeassistant/components/nest/climate.py
index dc4b0bd33ae..eec7108cdea 100644
--- a/homeassistant/components/nest/climate.py
+++ b/homeassistant/components/nest/climate.py
@@ -192,7 +192,10 @@ class NestThermostat(ClimateDevice):
     def hvac_mode(self):
         """Return current operation ie. heat, cool, idle."""
         if self._mode == NEST_MODE_ECO:
-            # We assume the first operation in operation list is the main one
+            if self.device.previous_mode in MODE_NEST_TO_HASS:
+                return MODE_NEST_TO_HASS[self.device.previous_mode]
+
+            # previous_mode not supported so return the first compatible mode
             return self._operation_list[0]
 
         return MODE_NEST_TO_HASS[self._mode]
@@ -270,7 +273,7 @@ class NestThermostat(ClimateDevice):
         if self._mode == NEST_MODE_ECO:
             return PRESET_ECO
 
-        return None
+        return PRESET_NONE
 
     @property
     def preset_modes(self):
@@ -294,7 +297,7 @@ class NestThermostat(ClimateDevice):
             if need_eco:
                 self.device.mode = NEST_MODE_ECO
             else:
-                self.device.mode = MODE_HASS_TO_NEST[self._operation_list[0]]
+                self.device.mode = self.device.previous_mode
 
     @property
     def fan_mode(self):