Put the define in the config.h file and conditionally defined it in the load.h file.

inc/config.h

@@ -56,5 +56,12 @@ const uint16_t GatePulses[5] = {250, 500, 750, 1000, 1250};
 const double Tau = 8250;
 
 
+/**
+ * @brief Hysteresis value
+ * Anything below this value will keep or turn on the associated 
+ * pin in thermostat mode.
+ */
+#define HYSTERESIS 900
+
 
 #endif //CONFIG_H

src/load/load.h

@@ -27,12 +27,10 @@
  */
 #define HIGHTHRESH 1000
 
-/**
- * @brief Hysteresis value
- * Anything below this value will keep or turn on the associated 
- * pin.
- */
+
+#ifndef HYSTERESIS
 #define HYSTERESIS 900
+#endif
 
 /**
  * @brief Checks if the adc pin is inbetween LOWTHRESH and HIGHTHRESH and then