From 2e4e3a42cc9c86d931e6d0e4a363fdb476403075 Mon Sep 17 00:00:00 2001
From: Zio Tibia <4745882+ziotibia81@users.noreply.github.com>
Date: Thu, 21 Dec 2017 14:24:19 +0100
Subject: [PATCH] Fix handling zero values for state_on/state_off (#11264)

---
 homeassistant/components/switch/modbus.py | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/homeassistant/components/switch/modbus.py b/homeassistant/components/switch/modbus.py
index c731b336dfb..211ff54d5a4 100644
--- a/homeassistant/components/switch/modbus.py
+++ b/homeassistant/components/switch/modbus.py
@@ -141,10 +141,17 @@ class ModbusRegisterSwitch(ModbusCoilSwitch):
         self._verify_register = (
             verify_register if verify_register else self._register)
         self._register_type = register_type
-        self._state_on = (
-            state_on if state_on else self._command_on)
-        self._state_off = (
-            state_off if state_off else self._command_off)
+
+        if state_on is not None:
+            self._state_on = state_on
+        else:
+            self._state_on = self._command_on
+
+        if state_off is not None:
+            self._state_off = state_off
+        else:
+            self._state_off = self._command_off
+
         self._is_on = None
 
     def turn_on(self, **kwargs):