diff --git a/src/devices/solar.cpp b/src/devices/solar.cpp
index 3f314cc97..07e32b89e 100644
--- a/src/devices/solar.cpp
+++ b/src/devices/solar.cpp
@@ -188,7 +188,7 @@ void Solar::process_SM100Status(std::shared_ptr<const Telegram> telegram) {
  * SM100Status2 - type 0x036A EMS+ for pump on/off at offset 0x0A - for SM100 and SM200
  * e.g. B0 00 FF 00 02 6A 03 03 03 03 01 03 03 03 03 03 01 03 
  * byte 4 = VS2 3-way valve for cylinder 2 : test=01, on=04 and off=03
- * byte 10 = PS1 Solar circuit pump for collector array 1: test=01, on=04 and off=03
+ * byte 10 = PS1 Solar circuit pump for collector array 1: test=b0001(1), on=b0100(4) and off=b0011(3)
  */
 void Solar::process_SM100Status2(std::shared_ptr<const Telegram> telegram) {
     telegram->read_bitvalue(valveStatus_, 4, 2); // on if bit 2 set
diff --git a/src/telegram.h b/src/telegram.h
index c574e1497..550c73c67 100644
--- a/src/telegram.h
+++ b/src/telegram.h
@@ -85,7 +85,7 @@ class Telegram {
             return; // out of bounds
         }
 
-        value = (uint8_t)(((message_data[index]) >> (bit)) & 0x01);
+        value = (uint8_t)(((message_data[index - offset]) >> (bit)) & 0x01);
     }
 
     // read values from a telegram. We always store the value, regardless if its garbage
diff --git a/src/test/test.cpp b/src/test/test.cpp
index 221ae5dbb..241487032 100644
--- a/src/test/test.cpp
+++ b/src/test/test.cpp
@@ -205,6 +205,15 @@ void Test::run_test(uuid::console::Shell & shell, const std::string & command) {
         EMSESP::show_values(shell);
 
         EMSESP::send_raw_telegram("B0 00 FF 18 02 62 80 00 B8");
+
+        uart_telegram("30 00 FF 0A 02 6A 04"); // SM100 pump on  1
+
+        EMSESP::rxservice_.loop();
+        EMSESP::show_values(shell);
+
+        uart_telegram("30 00 FF 0A 02 6A 03"); // SM100 pump off  0
+
+        EMSESP::rxservice_.loop();
         EMSESP::show_values(shell);
     }