diff --git a/components/truma_inetbox/LinBusListener.cpp b/components/truma_inetbox/LinBusListener.cpp
index e20ff59..5a16c0d 100644
--- a/components/truma_inetbox/LinBusListener.cpp
+++ b/components/truma_inetbox/LinBusListener.cpp
@@ -421,6 +421,16 @@ void LinBusListener::process_log_queue(TickType_t xTicksToWait) {
 }
 
 #ifdef USE_ESP32
+void LinBusListener::stream_send_test(const std::string &line) {
+  if (!this->stream_enabled_) return;
+  if (this->udp_sock_ < 0) this->stream_try_init_();
+  if (this->udp_sock_ < 0) return;
+  std::string msg = line;
+  if (msg.empty()) msg = "STREAM TEST";
+  msg.push_back('\n');
+  ::sendto(this->udp_sock_, msg.c_str(), msg.size(), 0, (struct sockaddr *) &this->udp_addr_, sizeof(this->udp_addr_));
+  this->last_stream_send_ms_ = millis();
+}
 void LinBusListener::stream_try_init_() {
   if (!this->stream_enabled_) return;
   if (this->udp_sock_ >= 0) return;
diff --git a/components/truma_inetbox/LinBusListener.h b/components/truma_inetbox/LinBusListener.h
index 6e25402..97c8cb0 100644
--- a/components/truma_inetbox/LinBusListener.h
+++ b/components/truma_inetbox/LinBusListener.h
@@ -48,6 +48,8 @@ class LinBusListener : public PollingComponent, public uart::UARTDevice {
   void set_fault_pin(GPIOPin *pin) { this->fault_pin_ = pin; }
   void set_observer_mode(bool val) { this->observer_mode_ = val; }
   bool get_lin_bus_fault() { return fault_on_lin_bus_reported_ > 3; }
+  // Send a manual UDP test line (when streaming is enabled)
+  void stream_send_test(const std::string &line);
 
   void process_lin_msg_queue(TickType_t xTicksToWait);
   void process_log_queue(TickType_t xTicksToWait);