diff --git a/RGBHardwareMonitor/__main__.py b/RGBHardwareMonitor/__main__.py
index 1131b87..7fd64f6 100644
--- a/RGBHardwareMonitor/__main__.py
+++ b/RGBHardwareMonitor/__main__.py
@@ -4,7 +4,9 @@
 import configparser
 import traceback
 from time import sleep
+from typing import Optional
 
+from RGBHardwareMonitor.hardware_monitor import HMNoSensorsError
 from . import runtime
 from . import rgb_serial
 from . import hardware_monitor
@@ -103,7 +105,23 @@ def real_main():
     rgb_serial.arduino_id = runtime.config['RGBHardwareMonitor']['arduino_serial_id']
 
     with RGBHardwareMonitorSysTray(animation_cls=WaitIconAnimation, start_animation=True) as systray:
-        rgb_serial.rings = ring_lights_from_cfg(runtime.config)  # TODO: Handle sensor doesn't exist exception
+        init_exc: Optional[Exception] = None
+        for _ in range(3):
+            try:
+                rgb_serial.rings = ring_lights_from_cfg(runtime.config)
+            except HMNoSensorsError as exc:
+                init_exc = exc
+                sleeptime: float = 5.0
+                logger.debug(f'Got no sensors found error. OpenHardwareMonitor initializing? Retrying in {sleeptime}')
+                sleep(sleeptime)
+            except Exception as exc:
+                init_exc = exc
+                raise
+            else:
+                init_exc = None
+                break
+        else:
+            raise RuntimeError(f'Initialization failed: {init_exc}') from init_exc
         while not quit_event.is_set():
             if not pause_event.is_set():
                 rgb_serial.update_loop(systray=systray)
diff --git a/RGBHardwareMonitor/hardware_monitor.py b/RGBHardwareMonitor/hardware_monitor.py
index 590e27b..fdef24e 100644
--- a/RGBHardwareMonitor/hardware_monitor.py
+++ b/RGBHardwareMonitor/hardware_monitor.py
@@ -12,6 +12,30 @@
 openhardwaremonitor_exe_path: Optional[str] = None
 
 
+class HardwareMonitorError(Exception):
+    """Base class for hardware monitor exceptions"""
+
+
+class HMExecError(HardwareMonitorError):
+    """Exception class for process execution errors"""
+
+
+class HMWMIError(HardwareMonitorError):
+    """Exception class for WMI related errors"""
+
+
+class HMWMINamespaceError(HMWMIError):
+    """Exception class for WMI namespace not found errors"""
+
+
+class HMNoSensorsError(HardwareMonitorError):
+    """Exception class for no sensors returned from WMI query"""
+
+
+class HMSensorNotFound(HardwareMonitorError):
+    """Exception class for sensor not found from WMI query"""
+
+
 # TODO: Catch WMI errors (like disconnection), check wmi lib
 
 
@@ -26,7 +50,7 @@ def is_openhardwaremonitor_running():
 
 def openhardwaremonitor_start():
     if openhardwaremonitor_exe_path is None:
-        raise ValueError('Cannot run OpenHardwareMonitor: executable path not specified')
+        raise HMExecError('Cannot run OpenHardwareMonitor: executable path not specified')
     run_dir = Path(openhardwaremonitor_exe_path).parent
     logger.debug('Starting OpenHardwareMonitor...')
     run_as_admin(openhardwaremonitor_exe_path, run_dir=str(run_dir))
@@ -38,7 +62,7 @@ def openhardwaremonitor_start():
             break
         retry -= 1
     else:
-        raise RuntimeError('Failed starting OpenHardwareMonitor: WMI timed out')
+        raise HMWMIError('Failed starting OpenHardwareMonitor: WMI timed out')
 
 
 @dataclass
@@ -213,7 +237,7 @@ def __post_init__(self, start_ohm):
         wmi_ohm = _wmi_get_ohm()
         if not is_openhardwaremonitor_running():
             if not start_ohm:
-                raise RuntimeError('Failed while querying OpenHardwareMonitor WMI namespace. OHM not running?')
+                raise HMWMINamespaceError('Failed while querying OpenHardwareMonitor WMI namespace. OHM not running?')
             openhardwaremonitor_start()
             wmi_ohm = _wmi_get_ohm()
         self.name = WMI().Win32_ComputerSystem()[0].Name
diff --git a/RGBHardwareMonitor/rgb_serial.py b/RGBHardwareMonitor/rgb_serial.py
index 2bba7ca..e61d472 100644
--- a/RGBHardwareMonitor/rgb_serial.py
+++ b/RGBHardwareMonitor/rgb_serial.py
@@ -8,7 +8,7 @@
 
 from .log import logger
 from .runtime import quit_event, pause_event
-from .hardware_monitor import SystemInfo, Sensor
+from .hardware_monitor import SystemInfo, Sensor, HMNoSensorsError, HMSensorNotFound
 from .systray import WaitIconAnimation, RunningIconAnimation
 
 
@@ -32,7 +32,10 @@ class SensorSpec:
     def __post_init__(self):
         if self.__class__.system_info is None:
             self.__class__.system_info = SystemInfo(start_ohm=True)
-        for sensor in getattr(self.__class__.system_info, self.device).sensors:
+        sensors = getattr(self.__class__.system_info, self.device).sensors
+        if not sensors:
+            raise HMNoSensorsError('No sensors available from hardware monitor')
+        for sensor in sensors:
             for f_attr, f_val in self.filters.items():
                 if getattr(sensor, f_attr) != f_val:  # if any filter fails, break loop
                     break
@@ -40,7 +43,7 @@ def __post_init__(self):
                 self.sensor = sensor
                 break
         else:
-            raise OSError(f'Sensor not found (device: {self.device}, filters: {str(self.filters)})')
+            raise HMSensorNotFound(f'Sensor not found (device: {self.device}, filters: {str(self.filters)})')
 
     @property
     def value(self):