diff --git a/README.md b/README.md
index dcbf032..5d56b02 100644
--- a/README.md
+++ b/README.md
@@ -88,7 +88,7 @@ wget -O - https://raw.githubusercontent.com/Eagleshot/GlacierCam/main/updateScri
 ## Software
 - [ ] Automatically set camera to reboot when power is on again
 - [ ] Add log level settings
-- [ ] Improved settings validation
+- [X] Improved settings validation
 - [x] Code review by Philip
 - [x] Improve the format of saved data -> e.g. use .yaml instead of a csv file so additional data can easily be added or different data versions can be used in future software
 - [ ] Enable watchdog
diff --git a/main.py b/main.py
index 9d0aaa2..a08abec 100644
--- a/main.py
+++ b/main.py
@@ -264,14 +264,13 @@ def get_cpu_serial():
 ###########################
 # Set voltage thresholds
 ###########################
-
 try:
     # If settings low voltage threshold exists
-    if 2.0 <= settings.get("low_voltage_threshold") <= 25.0 or settings.get("low_voltage_threshold") == 0:
+    if settings.get("low_voltage_threshold"):
         wittyPi.set_low_voltage_threshold(settings.get("low_voltage_threshold"))
 
     # If settings recovery voltage threshold exists
-    if 2.0 <= settings.get("recovery_voltage_threshold") <= 25.0 or settings.get("recovery_voltage_threshold") == 0:
+    if settings.get("recovery_voltage_threshold"):
         # Recovery voltage threshold must be equal or greater than low voltage threshold
         if settings.get("recovery_voltage_threshold") < settings.get("low_voltage_threshold"):
             settings.set("recovery_voltage_threshold", settings.get("low_voltage_threshold"))
@@ -340,17 +339,13 @@ def get_cpu_serial():
     logging.warning("Could not append new measurements to log: %s", str(e))
 
 ###########################
-# Upload diagnostics data
+# Upload extended diagnostics data
 ###########################
 try:
-    # fileserver.append_file("diagnostics.csv", "", FILE_PATH)
-
     # Upload WittyPi diagnostics
     if settings.get("uploadWittyPiDiagnostics") and CONNECTED_TO_SERVER:
-
-        fileserver.append_file("wittyPi.log", f"{FILE_PATH}wittypi/") # Witty Pi log
-        fileserver.append_file("schedule.log", f"{FILE_PATH}wittypi/") # Witty Pi schedule
-
+        fileserver.append_file("wittyPi.log", f"{FILE_PATH}wittypi/")
+        fileserver.append_file("schedule.log", f"{FILE_PATH}wittypi/")
 except Exception as e:
     logging.warning("Could not upload diagnostics data: %s", str(e))
 
diff --git a/witty_pi_4.py b/witty_pi_4.py
index fb4698b..5f722b7 100644
--- a/witty_pi_4.py
+++ b/witty_pi_4.py
@@ -118,12 +118,17 @@ def get_recovery_voltage_threshold(self) -> float:
     def set_low_voltage_threshold(self, voltage: float) -> float:
         '''Sets the low voltage threshold from the Witty Pi 4'''
         try:
-            if voltage != self.get_low_voltage_threshold():
-                low_voltage_threshold = self.run_command(f"set_low_voltage_threshold {int(voltage*10)}")
-                logging.info("Set low voltage threshold to: %s V", voltage)
-                return low_voltage_threshold
+            if 2.0 <= voltage <= 25.0 or voltage == 0:
+                if voltage != self.get_low_voltage_threshold():
+                    low_voltage_threshold = self.run_command(f"set_low_voltage_threshold {int(voltage*10)}")
+                    logging.info("Set low voltage threshold to: %s V", voltage)
+                    return low_voltage_threshold
+                
+                logging.info("Low voltage threshold already set to: %s V", voltage)
+
+            else:
+                logging.error("Voltage must be between 2.0 and 25.0 V (or 0 to disable).")
 
-            logging.info("Low voltage threshold already set to: %s V", voltage)
             return voltage
 
         except Exception as e:
@@ -134,12 +139,17 @@ def set_low_voltage_threshold(self, voltage: float) -> float:
     def set_recovery_voltage_threshold(self, voltage: float) -> float:
         '''Sets the recovery voltage threshold from the Witty Pi 4'''
         try:
-            if voltage != self.get_recovery_voltage_threshold():
-                recovery_voltage_threshold = self.run_command(f"set_recovery_voltage_threshold {int(voltage*10)}")
-                logging.info("Set recovery voltage threshold to: %s V", voltage)
-                return recovery_voltage_threshold
+            if 2.0 <= voltage <= 25.0 or voltage == 0:
+                if voltage != self.get_recovery_voltage_threshold():
+                    recovery_voltage_threshold = self.run_command(f"set_recovery_voltage_threshold {int(voltage*10)}")
+                    logging.info("Set recovery voltage threshold to: %s V", voltage)
+                    return recovery_voltage_threshold
+
+                logging.info("Recovery voltage threshold already set to: %s V", voltage)
 
-            logging.info("Recovery voltage threshold already set to: %s V", voltage)
+            else:
+                logging.error("Voltage must be between 2.0 and 25.0 V (or 0 to disable).")
+                
             return voltage
 
         except Exception as e: