Index: firmware/App/Controllers/Valves.c
===================================================================
diff -u -rc49ab370df876258ed3c805b33b2a2311a8ac0e3 -r3643a2e648ab2b216fd08579e56bdc02fb94836d
--- firmware/App/Controllers/Valves.c	(.../Valves.c)	(revision c49ab370df876258ed3c805b33b2a2311a8ac0e3)
+++ firmware/App/Controllers/Valves.c	(.../Valves.c)	(revision 3643a2e648ab2b216fd08579e56bdc02fb94836d)
@@ -1,6 +1,6 @@
 /**************************************************************************
 *
-* Copyright (c) 2024-2025 Diality Inc. - All Rights Reserved.
+* Copyright (c) 2024-2026 Diality Inc. - All Rights Reserved.
 *
 * THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
 * WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
@@ -35,7 +35,7 @@
 #define ENERGIZED                                       1                                                           ///< 1 for energized valve.
 #define ALL_VALVES_DEENERGIZED                          0x0000                                                      ///< 0 in U16 bit field for all valves.
 
-#define VALVE_PWM_PERIOD                                50                                                          ///< Valve PWM Period in 0.1 us res ( 20kHz )
+#define VALVE_PWM_PERIOD                                500                                                          ///< Valve PWM Period in 0.1 us res ( 20kHz )
 #define VALVE_PWM_LOW                                   ( VALVE_PWM_PERIOD * 0.2 )                                  ///< Valve low PWM percentage
 #define VALVE_PWM_PULL_IN                               100                                                         ///< Valve 'strike' period at 100% PWM in ms
 
@@ -174,7 +174,7 @@
         valveSPBits |= 0x01 << ( i - FIRST_SP_VALVE );
     }
 
-    for ( i = FIRST_IO_VALVE; i <= LAST_IO_VALVE; i++ )
+    for ( i = M12_VALV; i <= LAST_IO_VALVE; i++ )
     {
         valveIOBits |= 0x01 << ( i - FIRST_IO_VALVE );
     }
@@ -332,7 +332,7 @@
                  ( D26_VALV == valveID ) || ( D22_VALV == valveID ) || ( D80_VALV == valveID ) || ( D81_VALV == valveID ) || ( D79_PMP_VALV == valveID )   ||
                  ( P11_VALV == valveID ) || ( P33_VALV == valveID ) || ( P34_VALV == valveID ) || ( P37_VALV == valveID ) || ( P6_VALV == valveID ) ||
                  ( M12_VALV == valveID ) || ( P39_VALV == valveID ) || ( D83_VALV == valveID ) || ( D91_VALV == valveID ) || ( D100_VALV == valveID ) )
-         {
+            {
                 result = TRUE;
             }
             break;