diff --git a/libmbus/mbus/mbus-protocol.c b/libmbus/mbus/mbus-protocol.c
index 268867f..c6916f9 100644
--- a/libmbus/mbus/mbus-protocol.c
+++ b/libmbus/mbus/mbus-protocol.c
@@ -1086,8 +1086,8 @@ mbus_data_variable_medium_lookup(u_char medium)
             snprintf(buff, sizeof(buff), "Gas");
             break;
                                           
-        case MBUS_VARIABLE_DATA_MEDIUM_HEAT:
-            snprintf(buff, sizeof(buff), "Heat");
+        case MBUS_VARIABLE_DATA_MEDIUM_HEAT_OUT:
+            snprintf(buff, sizeof(buff), "Heat: Outlet");
             break;
 
         case MBUS_VARIABLE_DATA_MEDIUM_STEAM:
@@ -1117,10 +1117,22 @@ mbus_data_variable_medium_lookup(u_char medium)
         case MBUS_VARIABLE_DATA_MEDIUM_COOL_IN:
             snprintf(buff, sizeof(buff), "Cooling load meter: Inlet");
             break;
+            
+        case MBUS_VARIABLE_DATA_MEDIUM_HEAT_IN:
+            snprintf(buff, sizeof(buff), "Heat: Inlet");
+            break;
+            
+        case MBUS_VARIABLE_DATA_MEDIUM_HEAT_COOL:
+            snprintf(buff, sizeof(buff), "Heat / Cooling load meter");
+            break;
 
         case MBUS_VARIABLE_DATA_MEDIUM_BUS:
             snprintf(buff, sizeof(buff), "Bus/System");
             break;
+            
+        case MBUS_VARIABLE_DATA_MEDIUM_UNKNOWN:
+            snprintf(buff, sizeof(buff), "Unknown Medium");
+            break;
 
         case MBUS_VARIABLE_DATA_MEDIUM_COLD_WATER:
             snprintf(buff, sizeof(buff), "Cold water");
@@ -1138,10 +1150,7 @@ mbus_data_variable_medium_lookup(u_char medium)
             snprintf(buff, sizeof(buff), "A/D Converter");
             break;
 
-        case 0x0C:
-            snprintf(buff, sizeof(buff), "Heat (Volume measured at flow temperature: inlet)");
-            break;
-
+        case 0x10: // - 0x15
         case 0x20: // - 0xFF
             snprintf(buff, sizeof(buff), "Reserved");
             break;
diff --git a/libmbus/mbus/mbus-protocol.h b/libmbus/mbus/mbus-protocol.h
index 47612fc..d0596da 100644
--- a/libmbus/mbus/mbus-protocol.h
+++ b/libmbus/mbus/mbus-protocol.h
@@ -409,7 +409,7 @@ typedef struct _mbus_data_secondary_address {
 #define MBUS_VARIABLE_DATA_MEDIUM_OIL           0x01
 #define MBUS_VARIABLE_DATA_MEDIUM_ELECTRICITY   0x02
 #define MBUS_VARIABLE_DATA_MEDIUM_GAS           0x03
-#define MBUS_VARIABLE_DATA_MEDIUM_HEAT          0x04
+#define MBUS_VARIABLE_DATA_MEDIUM_HEAT_OUT      0x04
 #define MBUS_VARIABLE_DATA_MEDIUM_STEAM         0x05
 #define MBUS_VARIABLE_DATA_MEDIUM_HOT_WATER     0x06
 #define MBUS_VARIABLE_DATA_MEDIUM_WATER         0x07
@@ -417,7 +417,10 @@ typedef struct _mbus_data_secondary_address {
 #define MBUS_VARIABLE_DATA_MEDIUM_COMPR_AIR     0x09
 #define MBUS_VARIABLE_DATA_MEDIUM_COOL_OUT      0x0A
 #define MBUS_VARIABLE_DATA_MEDIUM_COOL_IN       0x0B
+#define MBUS_VARIABLE_DATA_MEDIUM_HEAT_IN       0x0C
+#define MBUS_VARIABLE_DATA_MEDIUM_HEAT_COOL     0x0D
 #define MBUS_VARIABLE_DATA_MEDIUM_BUS           0x0E
+#define MBUS_VARIABLE_DATA_MEDIUM_UNKNOWN       0x0F
 #define MBUS_VARIABLE_DATA_MEDIUM_COLD_WATER    0x16
 #define MBUS_VARIABLE_DATA_MEDIUM_DUAL_WATER    0x17
 #define MBUS_VARIABLE_DATA_MEDIUM_PRESSURE      0x18