diff --git a/.coveragerc b/.coveragerc
index 181c551e02a..6ad158066df 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -620,6 +620,7 @@ omit =
     homeassistant/components/mochad/*
     homeassistant/components/modbus/climate.py
     homeassistant/components/modbus/cover.py
+    homeassistant/components/modbus/modbus.py
     homeassistant/components/modbus/switch.py
     homeassistant/components/modem_callerid/sensor.py
     homeassistant/components/motion_blinds/__init__.py
diff --git a/homeassistant/components/modbus/modbus.py b/homeassistant/components/modbus/modbus.py
index ad53bd2aa53..f04c019e6a6 100644
--- a/homeassistant/components/modbus/modbus.py
+++ b/homeassistant/components/modbus/modbus.py
@@ -5,6 +5,7 @@ import threading
 from pymodbus.client.sync import ModbusSerialClient, ModbusTcpClient, ModbusUdpClient
 from pymodbus.constants import Defaults
 from pymodbus.exceptions import ModbusException
+from pymodbus.pdu import ExceptionResponse, IllegalFunctionRequest
 from pymodbus.transaction import ModbusRtuFramer
 
 from homeassistant.const import (
@@ -161,10 +162,11 @@ class ModbusHub:
         return self._config_name
 
     def _log_error(self, exception_error: ModbusException, error_state=True):
+        log_text = "Pymodbus: " + str(exception_error)
         if self._in_error:
-            _LOGGER.debug(str(exception_error))
+            _LOGGER.debug(log_text)
         else:
-            _LOGGER.error(str(exception_error))
+            _LOGGER.error(log_text)
             self._in_error = error_state
 
     def setup(self):
@@ -236,6 +238,9 @@ class ModbusHub:
             except ModbusException as exception_error:
                 self._log_error(exception_error)
                 return None
+            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                self._log_error(result)
+                return None
             self._in_error = False
             return result
 
@@ -248,6 +253,9 @@ class ModbusHub:
             except ModbusException as exception_error:
                 self._log_error(exception_error)
                 return None
+            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                self._log_error(result)
+                return None
             self._in_error = False
             return result
 
@@ -260,6 +268,9 @@ class ModbusHub:
             except ModbusException as exception_error:
                 self._log_error(exception_error)
                 return None
+            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                self._log_error(result)
+                return None
             self._in_error = False
             return result
 
@@ -272,6 +283,9 @@ class ModbusHub:
             except ModbusException as exception_error:
                 self._log_error(exception_error)
                 return None
+            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                self._log_error(result)
+                return None
             self._in_error = False
             return result
 
@@ -280,10 +294,13 @@ class ModbusHub:
         with self._lock:
             kwargs = {"unit": unit} if unit else {}
             try:
-                self._client.write_coil(address, value, **kwargs)
+                result = self._client.write_coil(address, value, **kwargs)
             except ModbusException as exception_error:
                 self._log_error(exception_error)
                 return False
+            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                self._log_error(result)
+                return False
             self._in_error = False
             return True
 
@@ -292,10 +309,13 @@ class ModbusHub:
         with self._lock:
             kwargs = {"unit": unit} if unit else {}
             try:
-                self._client.write_coils(address, values, **kwargs)
+                result = self._client.write_coils(address, values, **kwargs)
             except ModbusException as exception_error:
                 self._log_error(exception_error)
                 return False
+            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                self._log_error(result)
+                return False
             self._in_error = False
             return True
 
@@ -304,10 +324,13 @@ class ModbusHub:
         with self._lock:
             kwargs = {"unit": unit} if unit else {}
             try:
-                self._client.write_register(address, value, **kwargs)
+                result = self._client.write_register(address, value, **kwargs)
             except ModbusException as exception_error:
                 self._log_error(exception_error)
                 return False
+            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                self._log_error(result)
+                return False
             self._in_error = False
             return True
 
@@ -316,9 +339,12 @@ class ModbusHub:
         with self._lock:
             kwargs = {"unit": unit} if unit else {}
             try:
-                self._client.write_registers(address, values, **kwargs)
+                result = self._client.write_registers(address, values, **kwargs)
             except ModbusException as exception_error:
                 self._log_error(exception_error)
                 return False
+            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                self._log_error(result)
+                return False
             self._in_error = False
             return True