diff --git a/src/console.cpp b/src/console.cpp
index 419eb8082..fa3992ae6 100644
--- a/src/console.cpp
+++ b/src/console.cpp
@@ -65,7 +65,11 @@ void EMSESPShell::display_banner() {
 
     println();
     printfln(F("┌──────────────────────────────────────────┐"));
+#if defined(ESP32)
+    printfln(F("│ %sEMS-ESP version %-10s ESP32%s         │"), COLOR_BOLD_ON, settings.app_version().c_str(), COLOR_BOLD_OFF);
+#else
     printfln(F("│ %sEMS-ESP version %-10s%s               │"), COLOR_BOLD_ON, settings.app_version().c_str(), COLOR_BOLD_OFF);
+#endif
     printfln(F("│ %s%shttps://github.com/proddy/EMS-ESP%s        │"), COLOR_BRIGHT_GREEN, COLOR_UNDERLINE, COLOR_RESET);
     printfln(F("│                                          │"));
 
diff --git a/src/devices/boiler.cpp b/src/devices/boiler.cpp
index 0e6309ca7..26f804142 100644
--- a/src/devices/boiler.cpp
+++ b/src/devices/boiler.cpp
@@ -51,7 +51,6 @@ Boiler::Boiler(uint8_t device_type, int8_t device_id, uint8_t product_id, const
     // the telegram handlers...
     register_telegram_type(0x10, F("UBAErrorMessage1"), false, std::bind(&Boiler::process_UBAErrorMessage, this, _1));
     register_telegram_type(0x11, F("UBAErrorMessage2"), false, std::bind(&Boiler::process_UBAErrorMessage, this, _1));
-    register_telegram_type(0x12, F("UBAErrorMessage3"), false, std::bind(&Boiler::process_UBAErrorMessage, this, _1));
     register_telegram_type(0x18, F("UBAMonitorFast"), false, std::bind(&Boiler::process_UBAMonitorFast, this, _1));
     register_telegram_type(0x19, F("UBAMonitorSlow"), true, std::bind(&Boiler::process_UBAMonitorSlow, this, _1));
     register_telegram_type(0x34, F("UBAMonitorWW"), false, std::bind(&Boiler::process_UBAMonitorWW, this, _1));
diff --git a/src/devices/solar.cpp b/src/devices/solar.cpp
index 61ed8e5eb..68cd990e0 100644
--- a/src/devices/solar.cpp
+++ b/src/devices/solar.cpp
@@ -36,8 +36,7 @@ Solar::Solar(uint8_t device_type, uint8_t device_id, uint8_t product_id, const s
     register_telegram_type(0x0097, F("SM10Monitor"), true, std::bind(&Solar::process_SM10Monitor, this, _1));
     register_telegram_type(0x0362, F("SM100Monitor"), true, std::bind(&Solar::process_SM100Monitor, this, _1));
     register_telegram_type(0x0363, F("SM100Monitor2"), true, std::bind(&Solar::process_SM100Monitor2, this, _1));
-
-    register_telegram_type(0x0363, F("SM100Config"), true, std::bind(&Solar::process_SM100Config, this, _1));
+    register_telegram_type(0x0366, F("SM100Config"), true, std::bind(&Solar::process_SM100Config, this, _1));
 
     register_telegram_type(0x0364, F("SM100Status"), false, std::bind(&Solar::process_SM100Status, this, _1));
     register_telegram_type(0x036A, F("SM100Status2"), false, std::bind(&Solar::process_SM100Status2, this, _1));
diff --git a/src/emsesp.cpp b/src/emsesp.cpp
index dee34067a..30a67f0a0 100644
--- a/src/emsesp.cpp
+++ b/src/emsesp.cpp
@@ -568,14 +568,15 @@ void EMSESP::send_write_request(const uint16_t type_id,
 // this is main entry point when data is received on the Rx line, via emsuart library
 // we check if its a complete telegram or just a single byte (which could be a poll or a return status)
 void EMSESP::incoming_telegram(uint8_t * data, const uint8_t length) {
-    // LOG_DEBUG(F("Rx: %s"), Helpers::data_to_hex(data, length).c_str());
+    static uint32_t tx_time_ = 0;
     // check first for echo
     uint8_t first_value = data[0];
     if (((first_value & 0x7F) == txservice_.ems_bus_id()) && (length > 1)) {
         // if we ask ourself at roomcontrol for version e.g. 0B 98 02 00 20
         Roomctrl::check((data[1] ^ 0x80 ^ rxservice_.ems_mask()), data);
 #ifdef EMSESP_DEBUG
-        LOG_DEBUG(F("[DEBUG] Echo: %s"), Helpers::data_to_hex(data, length).c_str());
+        // get_uptime is only updated once per loop, does not give the right time 
+        LOG_DEBUG(F("[DEBUG] Echo after %d ms: %s"), ::millis() - tx_time_, Helpers::data_to_hex(data, length).c_str());
 #endif
         return; // it's an echo
     }
@@ -638,6 +639,7 @@ void EMSESP::incoming_telegram(uint8_t * data, const uint8_t length) {
         // if ht3 poll must be ems_bus_id else if Buderus poll must be (ems_bus_id | 0x80)
         if ((first_value ^ 0x80 ^ rxservice_.ems_mask()) == txservice_.ems_bus_id()) {
             EMSbus::last_bus_activity(uuid::get_uptime()); // set the flag indication the EMS bus is active
+            tx_time_ = ::millis(); // get_uptime is only updated once per loop, does not give the right time 
             txservice_.send();
         }
         // send remote room temperature if active
@@ -731,7 +733,7 @@ void EMSESP::console_commands(Shell & shell, unsigned int context) {
                                        flash_string_vector{F_(n_mandatory)},
                                        [](Shell & shell, const std::vector<std::string> & arguments) {
                                            uint8_t tx_mode = std::strtol(arguments[0].c_str(), nullptr, 10);
-                                           if ((tx_mode > 0) && (tx_mode <= 30)) {
+                                           if ((tx_mode > 0) && (tx_mode <= 50)) {
                                                Settings settings;
                                                settings.ems_tx_mode(tx_mode);
                                                settings.commit();
diff --git a/src/helpers.cpp b/src/helpers.cpp
index ddb128ebe..bd9c3a9ea 100644
--- a/src/helpers.cpp
+++ b/src/helpers.cpp
@@ -104,7 +104,7 @@ char * Helpers::render_value(char * result, uint8_t value, uint8_t format) {
         return (result);
     }
 
-    static char s2[5] = {0};
+    char s2[5] = {0};
 
     switch (format) {
     case 2:
@@ -226,7 +226,7 @@ char * Helpers::render_value(char * result, const uint32_t value, const uint8_t
         return (result);
     }
 
-    static char s[20] = {0};
+    char s[20] = {0};
 
 #ifndef EMSESP_STANDALONE
     if (format <= 1) {
diff --git a/src/system.cpp b/src/system.cpp
index 27d0bc1f3..4b1b38eb1 100644
--- a/src/system.cpp
+++ b/src/system.cpp
@@ -206,7 +206,11 @@ void System::start() {
     settings.app_version(EMSESP_APP_VERSION);
     settings.commit();
 
+#if defined(ESP32)
+    LOG_INFO(F("System booted (EMS-ESP version %s ESP32)"), settings.app_version().c_str());
+#else
     LOG_INFO(F("System booted (EMS-ESP version %s)"), settings.app_version().c_str());
+#endif
 
     if (LED_GPIO) {
         pinMode(LED_GPIO, OUTPUT); // LED pin, 0 is disabled
diff --git a/src/telegram.cpp b/src/telegram.cpp
index 7ee6bd0b1..cc4fb0335 100644
--- a/src/telegram.cpp
+++ b/src/telegram.cpp
@@ -461,6 +461,11 @@ void TxService::send_telegram(const QueuedTxTelegram & tx_telegram) {
 
     length++; // add one since we want to now include the CRC
 
+#if defined(ESP8266)
+    Settings  settings;
+    if (settings.ems_tx_mode() <= 4) {
+#endif
+    // This logging causes errors with timer based tx-modes on esp8266!
     LOG_DEBUG(F("Sending %s Tx [#%d], telegram: %s"),
               (telegram->operation == Telegram::Operation::TX_WRITE) ? F("write") : F("read"),
               tx_telegram.id_,
@@ -472,7 +477,9 @@ void TxService::send_telegram(const QueuedTxTelegram & tx_telegram) {
         LOG_NOTICE(F("[DEBUG] Tx: %s"), Helpers::data_to_hex(telegram_raw, length).c_str());
     }
 #endif
-
+#if defined(ESP8266)
+    }
+#endif
     // send the telegram to the UART Tx
     uint16_t status = EMSuart::transmit(telegram_raw, length);
 
@@ -497,13 +504,10 @@ void TxService::send_telegram(const uint8_t * data, const uint8_t length) {
     }
     telegram_raw[length] = calculate_crc(telegram_raw, length); // apppend CRC
 
-    LOG_DEBUG(F("Sending Raw telegram: %s (length=%d)"), Helpers::data_to_hex(telegram_raw, length).c_str(), length);
-
     tx_waiting(false); // no post validation
 
     // send the telegram to the UART Tx
     uint16_t status = EMSuart::transmit(telegram_raw, length);
-    //LOG_DEBUG(F("Tx: %s"), Helpers::data_to_hex(telegram_raw, length).c_str());
 
     if (status == EMS_TX_STATUS_ERR) {
         LOG_ERROR(F("Failed to transmit Tx via UART."));
diff --git a/src/uart/emsuart_esp32.cpp b/src/uart/emsuart_esp32.cpp
index 111457217..c93e4b2ad 100644
--- a/src/uart/emsuart_esp32.cpp
+++ b/src/uart/emsuart_esp32.cpp
@@ -33,11 +33,10 @@ static RingbufHandle_t buf_handle   = NULL;
 static hw_timer_t *    timer        = NULL;
 bool                   drop_next_rx = true;
 uint8_t                tx_mode_     = 0xFF;
-//portMUX_TYPE           timerMux     = portMUX_INITIALIZER_UNLOCKED;
-uint8_t  emsTxBuf[EMS_MAXBUFFERSIZE];
-uint8_t  emsTxBufIdx;
-uint8_t  emsTxBufLen;
-uint32_t emsTxWait;
+uint8_t                emsTxBuf[EMS_MAXBUFFERSIZE];
+uint8_t                emsTxBufIdx;
+uint8_t                emsTxBufLen;
+uint32_t               emsTxWait;
 
 /*
 * Task to handle the incoming data
@@ -63,6 +62,10 @@ void IRAM_ATTR EMSuart::emsuart_rx_intr_handler(void * para) {
 
     if (EMS_UART.int_st.brk_det) {
         EMS_UART.int_clr.brk_det = 1; // clear flag
+        if (emsTxBufIdx < emsTxBufLen) { // timer tx_mode is interrupted by <brk>
+            emsTxBufIdx = emsTxBufLen;   // stop timer mode
+            drop_next_rx = true;         // we have trash in buffer
+        }
         length                   = 0;
         while (EMS_UART.status.rxfifo_cnt) {
             uint8_t rx = EMS_UART.fifo.rw_byte; // read all bytes from fifo
@@ -82,7 +85,7 @@ void IRAM_ATTR EMSuart::emsuart_rx_intr_handler(void * para) {
 
 
 void IRAM_ATTR EMSuart::emsuart_tx_timer_intr_handler() {
-    if (emsTxBufIdx > 32) {
+    if (emsTxBufIdx > EMS_MAXBUFFERSIZE) {
         return;
     }
 
@@ -92,7 +95,7 @@ void IRAM_ATTR EMSuart::emsuart_tx_timer_intr_handler() {
         EMS_UART.fifo.rw_byte = emsTxBuf[emsTxBufIdx];
         timerAlarmWrite(timer, emsTxWait, false);
         timerAlarmEnable(timer);
-    } else if (emsTxBufIdx == emsTxBufLen) {
+    } else  if (emsTxBufIdx == emsTxBufLen) {
         EMS_UART.conf0.txd_brk = 1; // <brk> after send
     }
 }
@@ -101,24 +104,12 @@ void IRAM_ATTR EMSuart::emsuart_tx_timer_intr_handler() {
  * init UART driver
  */
 void EMSuart::start(uint8_t tx_mode) {
-    if (tx_mode == EMS_TXMODE_DEFAULT) {
-        emsTxWait = EMSUART_BIT_TIME * 11;
-    } else if (tx_mode == EMS_TXMODE_EMSPLUS) {
-        emsTxWait = EMSUART_BIT_TIME * 20;
-    } else if (tx_mode == EMS_TXMODE_HT3) {
-        emsTxWait = EMSUART_BIT_TIME * 17;
-    } else if (tx_mode > 10) {
-        emsTxWait = EMSUART_BIT_TIME * tx_mode;
-    } else if (tx_mode > 5) {
-        emsTxWait = EMSUART_BIT_TIME * tx_mode * 2;
-    }
-
+    emsTxWait = EMSUART_TX_BIT_TIME * (tx_mode + 10);
     if (tx_mode_ != 0xFF) { // uart already initialized
         tx_mode_ = tx_mode;
         restart();
         return;
     }
-
     tx_mode_ = tx_mode;
 
     uart_config_t uart_config = {
@@ -128,23 +119,22 @@ void EMSuart::start(uint8_t tx_mode) {
         .stop_bits = UART_STOP_BITS_1,
         .flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
     };
-
-    ESP_ERROR_CHECK(uart_param_config(EMSUART_UART, &uart_config));
-    ESP_ERROR_CHECK(uart_set_pin(EMSUART_UART, EMSUART_TXPIN, EMSUART_RXPIN, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE));
+    uart_param_config(EMSUART_UART, &uart_config);
+    uart_set_pin(EMSUART_UART, EMSUART_TXPIN, EMSUART_RXPIN, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
     EMS_UART.int_ena.val             = 0;          // disable all intr.
     EMS_UART.int_clr.val             = 0xFFFFFFFF; // clear all intr. flags
     EMS_UART.idle_conf.tx_brk_num    = 11;         // breaklength 11 bit
     EMS_UART.idle_conf.rx_idle_thrhd = 256;
     drop_next_rx                     = true;
     buf_handle                       = xRingbufferCreate(128, RINGBUF_TYPE_NOSPLIT);
-    ESP_ERROR_CHECK(uart_isr_register(EMSUART_UART, emsuart_rx_intr_handler, NULL, ESP_INTR_FLAG_IRAM, &uart_handle));
+    uart_isr_register(EMSUART_UART, emsuart_rx_intr_handler, NULL, ESP_INTR_FLAG_IRAM, &uart_handle);
     xTaskCreate(emsuart_recvTask, "emsuart_recvTask", 2048, NULL, configMAX_PRIORITIES - 1, NULL);
     EMS_UART.int_ena.brk_det = 1; // activate only break
 
     emsTxBufIdx = 0;
     emsTxBufLen = 0;
-    timer       = timerBegin(1, 80, true);                             // timer prescale to 1 µs, countup
-    timerAttachInterrupt(timer, &emsuart_tx_timer_intr_handler, true); // Timer with edge interrupt
+    timer = timerBegin(1, 80, true); // timer prescale to 1 µs, countup
+	timerAttachInterrupt(timer, &emsuart_tx_timer_intr_handler, true); // Timer with edge interrupt
 }
 
 /*
@@ -152,7 +142,7 @@ void EMSuart::start(uint8_t tx_mode) {
  */
 void EMSuart::stop() {
     EMS_UART.int_ena.val = 0; // disable all intr.
-                              // timerAlarmDisable(timer);
+	// timerAlarmDisable(timer);
 };
 
 /*
@@ -163,25 +153,45 @@ void EMSuart::restart() {
         EMS_UART.int_clr.brk_det = 1;    // clear flag
         drop_next_rx             = true; // and drop first frame
     }
-
     EMS_UART.int_ena.brk_det = 1; // activate only break
     emsTxBufIdx              = 0;
     emsTxBufLen              = 0;
-};
+}
 
 /*
  * Sends a 1-byte poll, ending with a <BRK>
  */
 void EMSuart::send_poll(uint8_t data) {
-    if (tx_mode_ == EMS_TXMODE_NEW || tx_mode_ == 5) {
-        EMS_UART.fifo.rw_byte  = data;
-        EMS_UART.conf0.txd_brk = 1; // <brk> after send
-    } else {
+    // if (tx_mode_ >= 6 || tx_mode_ < 4) { // modes 1, 2, 3 also here
+    if (tx_mode_ >= 5) {
         EMS_UART.fifo.rw_byte = data;
         emsTxBufIdx           = 0;
         emsTxBufLen           = 1;
         timerAlarmWrite(timer, emsTxWait, false);
         timerAlarmEnable(timer);
+    } else if (tx_mode_ == EMS_TXMODE_NEW) {
+        EMS_UART.fifo.rw_byte  = data;
+        EMS_UART.conf0.txd_brk = 1; // <brk> after send
+    } else if (tx_mode_ == EMS_TXMODE_HT3) {
+        EMS_UART.fifo.rw_byte  = data;
+        delayMicroseconds(EMSUART_TX_WAIT_HT3);
+        EMS_UART.conf0.txd_brk = 1; // <brk>
+        // delayMicroseconds(EMSUART_TX_WAIT_BRK);
+        // EMS_UART.conf0.txd_brk = 0;
+    } else if (tx_mode_ == EMS_TXMODE_EMSPLUS) {
+        EMS_UART.fifo.rw_byte  = data;
+        delayMicroseconds(EMSUART_TX_WAIT_PLUS);
+        EMS_UART.conf0.txd_brk = 1; // <brk>
+        // delayMicroseconds(EMSUART_TX_WAIT_BRK);
+        // EMS_UART.conf0.txd_brk = 0;
+    } else {
+        volatile uint8_t _usrxc = EMS_UART.status.rxfifo_cnt;
+        EMS_UART.fifo.rw_byte   = data;
+        uint8_t timeoutcnt      = EMSUART_TX_TIMEOUT;
+        while ((EMS_UART.status.rxfifo_cnt == _usrxc) && (--timeoutcnt > 0)) {
+            delayMicroseconds(EMSUART_TX_BUSY_WAIT); // burn CPU cycles...
+        }
+        EMS_UART.conf0.txd_brk = 1; // <brk>
     }
 }
 
@@ -191,16 +201,11 @@ void EMSuart::send_poll(uint8_t data) {
  * returns code, 1=success
  */
 uint16_t EMSuart::transmit(uint8_t * buf, uint8_t len) {
-    if (len == 0 || len > 32) {
+    if (len == 0 || len >= EMS_MAXBUFFERSIZE) {
         return EMS_TX_STATUS_ERR;
     }
-
-    if (tx_mode_ == EMS_TXMODE_NEW || tx_mode_ == 5) {
-        for (uint8_t i = 0; i < len; i++) {
-            EMS_UART.fifo.rw_byte = buf[i];
-        }
-        EMS_UART.conf0.txd_brk = 1; // <brk> after send
-    } else {
+    // if (tx_mode_ >= 6 || tx_mode_ < 4) { // timer controlled modes, also modes 1, 2, 3 because delays not working
+    if (tx_mode_ >= 5) { // timer controlled modes
         for (uint8_t i = 0; i < len; i++) {
             emsTxBuf[i] = buf[i];
         }
@@ -209,8 +214,50 @@ uint16_t EMSuart::transmit(uint8_t * buf, uint8_t len) {
         emsTxBufLen           = len;
         timerAlarmWrite(timer, emsTxWait, false);
         timerAlarmEnable(timer);
+        return EMS_TX_STATUS_OK;
     }
-
+    if (tx_mode_ == EMS_TXMODE_NEW) { // hardware controlled modes
+        for (uint8_t i = 0; i < len; i++) {
+            EMS_UART.fifo.rw_byte = buf[i];
+        }
+        EMS_UART.conf0.txd_brk = 1; // <brk> after send
+        return EMS_TX_STATUS_OK;
+    }
+    if (tx_mode_ == EMS_TXMODE_EMSPLUS) { // EMS+ with long delay
+        for (uint8_t i = 0; i < len; i++) {
+            EMS_UART.fifo.rw_byte = buf[i];
+            delayMicroseconds(EMSUART_TX_WAIT_PLUS);
+        }
+        EMS_UART.conf0.txd_brk = 1; // <brk> after send, cleard by hardware after send
+        // delayMicroseconds(EMSUART_TX_WAIT_BRK);
+        // EMS_UART.conf0.txd_brk = 0;
+        return EMS_TX_STATUS_OK;
+    }
+    if (tx_mode_ == EMS_TXMODE_HT3) { // HT3 with 7 bittimes delay
+        for (uint8_t i = 0; i < len; i++) {
+            EMS_UART.fifo.rw_byte = buf[i];
+            delayMicroseconds(EMSUART_TX_WAIT_HT3);
+        }
+        EMS_UART.conf0.txd_brk = 1; // <brk> after send, cleard by hardware after send
+        // delayMicroseconds(EMSUART_TX_WAIT_BRK);
+        // EMS_UART.conf0.txd_brk = 0;
+        return EMS_TX_STATUS_OK;
+    }
+    // mode 1 
+    // flush fifos -- not supported in ESP32 uart #2!
+    // EMS_UART.conf0.rxfifo_rst = 1;
+    // EMS_UART.conf0.txfifo_rst = 1;
+    for (uint8_t i = 0; i < len; i++) {
+        volatile uint8_t _usrxc = EMS_UART.status.rxfifo_cnt;
+        EMS_UART.fifo.rw_byte   = buf[i]; // send each Tx byte
+        uint8_t timeoutcnt      = EMSUART_TX_TIMEOUT;
+        while ((EMS_UART.status.rxfifo_cnt == _usrxc) && (--timeoutcnt > 0)) {
+            delayMicroseconds(EMSUART_TX_BUSY_WAIT); // burn CPU cycles...
+        }
+    }
+    EMS_UART.conf0.txd_brk = 1; // <brk> after send, cleard by hardware after send
+    // delayMicroseconds(EMSUART_TX_WAIT_BRK);
+    // EMS_UART.conf0.txd_brk = 0;
     return EMS_TX_STATUS_OK;
 }
 
diff --git a/src/uart/emsuart_esp32.h b/src/uart/emsuart_esp32.h
index e2fe0149b..5e332ea07 100644
--- a/src/uart/emsuart_esp32.h
+++ b/src/uart/emsuart_esp32.h
@@ -38,13 +38,27 @@
 #define EMSUART_UART UART_NUM_2 // on the ESP32 we're using UART2
 #define EMS_UART UART2          // for intr setting
 #define EMSUART_BAUD 9600       // uart baud rate for the EMS circuit
-#define EMSUART_BIT_TIME 104    // bit time @9600 baud
 
 #define EMS_TXMODE_DEFAULT 1
 #define EMS_TXMODE_EMSPLUS 2
 #define EMS_TXMODE_HT3 3
 #define EMS_TXMODE_NEW 4 // for michael's testing
 
+// LEGACY
+#define EMSUART_TX_BIT_TIME 104  // bit time @9600 baud
+#define EMSUART_TX_WAIT_BRK (EMSUART_TX_BIT_TIME * 11) // 1144
+
+// EMS 1.0
+#define EMSUART_TX_BUSY_WAIT (EMSUART_TX_BIT_TIME / 8) // 13
+#define EMSUART_TX_TIMEOUT (22 * EMSUART_TX_BIT_TIME / EMSUART_TX_BUSY_WAIT) // 176
+
+// HT3/Junkers - Time to send one Byte (8 Bits, 1 Start Bit, 1 Stop Bit) plus 7 bit delay. The -8 is for lag compensation.
+// since we use a faster processor the lag is negligible
+#define EMSUART_TX_WAIT_HT3 (EMSUART_TX_BIT_TIME * 17) // 1768
+
+// EMS+ - Time to send one Byte (8 Bits, 1 Start Bit, 1 Stop Bit) and delay of another Bytetime.
+#define EMSUART_TX_WAIT_PLUS (EMSUART_TX_BIT_TIME * 20) // 2080
+
 
 // customize the GPIO pins for RX and TX here
 #ifdef WEMOS_D1_32
diff --git a/src/uart/emsuart_esp8266.cpp b/src/uart/emsuart_esp8266.cpp
index e0d21c577..faedc23d8 100644
--- a/src/uart/emsuart_esp8266.cpp
+++ b/src/uart/emsuart_esp8266.cpp
@@ -30,11 +30,11 @@ EMSuart::EMSRxBuf_t * paEMSRxBuf[EMS_MAXBUFFERS];
 uint8_t               emsRxBufIdx  = 0;
 uint8_t               tx_mode_     = 0xFF;
 bool                  drop_next_rx = true;
-// uint32_t              emsRxTime;
-uint8_t  emsTxBuf[EMS_MAXBUFFERSIZE];
-uint8_t  emsTxBufIdx;
-uint8_t  emsTxBufLen;
-uint32_t emsTxWait;
+uint8_t               emsTxBuf[EMS_MAXBUFFERSIZE];
+uint8_t               emsTxBufIdx;
+uint8_t               emsTxBufLen;
+uint32_t              emsTxWait;
+
 
 //
 // Main interrupt handler
@@ -46,8 +46,10 @@ void ICACHE_RAM_ATTR EMSuart::emsuart_rx_intr_handler(void * para) {
 
     if (USIS(EMSUART_UART) & ((1 << UIBD))) { // BREAK detection = End of EMS data block
         USC0(EMSUART_UART) &= ~(1 << UCBRK);  // reset tx-brk
-        // just for testing if break isn't finished yet
-        // while((USS(EMSUART_UART) >> USRXD) == 0); // wait for idle state of pin
+        if (emsTxBufIdx < emsTxBufLen) { // timer tx_mode is interrupted by <brk>
+            emsTxBufIdx = emsTxBufLen;   // stop timer mode
+            drop_next_rx = true;         // we have trash in buffer
+        }
         USIC(EMSUART_UART) = (1 << UIBD); // INT clear the BREAK detect interrupt
         length             = 0;
         while ((USS(EMSUART_UART) >> USRXC) & 0x0FF) { // read fifo into buffer
@@ -61,7 +63,6 @@ void ICACHE_RAM_ATTR EMSuart::emsuart_rx_intr_handler(void * para) {
         if (!drop_next_rx) {
             pEMSRxBuf->length = length;
             os_memcpy((void *)pEMSRxBuf->buffer, (void *)&uart_buffer, pEMSRxBuf->length); // copy data into transfer buffer, including the BRK 0x00 at the end
-            // emsRxTime = uuid::get_uptime();
         }
         drop_next_rx = false;
         system_os_post(EMSUART_recvTaskPrio, 0, 0); // call emsuart_recvTask() at next opportunity
@@ -79,16 +80,8 @@ void ICACHE_FLASH_ATTR EMSuart::emsuart_recvTask(os_event_t * events) {
     uint8_t length        = pCurrent->length;                           // number of bytes including the BRK at the end
     pCurrent->length      = 0;
 
-    // it's a poll or status code, single byte and ok to send on, then quit
-    if (length == 2) {
-        EMSESP::incoming_telegram((uint8_t *)pCurrent->buffer, 1);
-        return;
-    }
-
-    // ignore double BRK at the end, possibly from the Tx loopback
-    // also telegrams with no data value
-    // then transmit EMS buffer, excluding the BRK
-    if (length > 4) {
+    // Ignore telegrams with no data value, then transmit EMS buffer, excluding the BRK
+    if (length > 4 || length == 2) {
         EMSESP::incoming_telegram((uint8_t *)pCurrent->buffer, length - 1);
     }
 }
@@ -97,9 +90,8 @@ void ICACHE_FLASH_ATTR EMSuart::emsuart_recvTask(os_event_t * events) {
  * flush everything left over in buffer, this clears both rx and tx FIFOs
  */
 void ICACHE_FLASH_ATTR EMSuart::emsuart_flush_fifos() {
-    uint32_t tmp = ((1 << UCRXRST) | (1 << UCTXRST)); // bit mask
-    USC0(EMSUART_UART) |= (tmp);                      // set bits
-    USC0(EMSUART_UART) &= ~(tmp);                     // clear bits
+    USC0(EMSUART_UART) |= ((1 << UCRXRST) | (1 << UCTXRST));  // set bits
+    USC0(EMSUART_UART) &= ~((1 << UCRXRST) | (1 << UCTXRST)); // clear bits
 }
 
 // ISR to Fire when Timer is triggered
@@ -107,54 +99,33 @@ void ICACHE_RAM_ATTR EMSuart::emsuart_tx_timer_intr_handler() {
     if (emsTxBufIdx > EMS_MAXBUFFERSIZE) {
         return;
     }
-
     emsTxBufIdx++;
     if (emsTxBufIdx < emsTxBufLen) {
         USF(EMSUART_UART) = emsTxBuf[emsTxBufIdx];
         timer1_write(emsTxWait);
     } else if (emsTxBufIdx == emsTxBufLen) {
         USC0(EMSUART_UART) |= (1 << UCBRK); // set <BRK>
-        if (tx_mode_ > 5 || tx_mode_ < 11) {
-            timer1_write(5 * EMSUART_TX_BIT_TIME * 11);
-            USIE(EMSUART_UART) &= ~(1 << UIBD); // disable break interrupt
-        }
-    } else if (USC0(EMSUART_UART) & (1 << UCBRK)) {
-        USC0(EMSUART_UART) &= ~(1 << UCBRK); // clear <BRK>
-        USIE(EMSUART_UART) |= (1 << UIBD);   // enable break interrupt
     }
 }
-
 /*
  * init UART0 driver
  */
 void ICACHE_FLASH_ATTR EMSuart::start(uint8_t tx_mode) {
-    if (tx_mode > 10) {
-        emsTxWait = 5 * EMSUART_TX_BIT_TIME * tx_mode; // bittimes for tx_mode
-    } else if (tx_mode > 5) {
-        emsTxWait = 10 * EMSUART_TX_BIT_TIME * tx_mode; // bittimes for tx_mode
+    if (tx_mode >= 5) {
+        emsTxWait = 5 * EMSUART_TX_BIT_TIME * (tx_mode + 10); // bittimes for tx_mode
     }
-
-    if (tx_mode == 5) {
-        USC0(EMSUART_UART) = 0x2C; // 8N1,5
-    } else {
-        USC0(EMSUART_UART) = EMSUART_CONFIG; // 8N1
-    }
-
     if (tx_mode_ != 0xFF) { // it's a restart no need to configure uart
         tx_mode_ = tx_mode;
         restart();
         return;
     }
-
     tx_mode_ = tx_mode;
-
     // allocate and preset EMS Receive buffers
     for (int i = 0; i < EMS_MAXBUFFERS; i++) {
         EMSRxBuf_t * p = (EMSRxBuf_t *)malloc(sizeof(EMSRxBuf_t));
         p->length      = 0;
         paEMSRxBuf[i]  = p;
     }
-
     pEMSRxBuf = paEMSRxBuf[0]; // reset EMS Rx Buffer
 
     ETS_UART_INTR_DISABLE();
@@ -166,7 +137,9 @@ void ICACHE_FLASH_ATTR EMSuart::start(uint8_t tx_mode) {
     PIN_PULLUP_DIS(PERIPHS_IO_MUX_U0RXD_U);
     PIN_FUNC_SELECT(PERIPHS_IO_MUX_U0RXD_U, FUNC_U0RXD);
 
-    USD(EMSUART_UART) = (UART_CLK_FREQ / EMSUART_BAUD);
+    // set 9600, 8 bits, no parity check, 1 stop bit
+    USD(EMSUART_UART)  = (UART_CLK_FREQ / EMSUART_BAUD);
+    USC0(EMSUART_UART) = EMSUART_CONFIG; // 8N1
 
     emsuart_flush_fifos();
 
@@ -180,7 +153,7 @@ void ICACHE_FLASH_ATTR EMSuart::start(uint8_t tx_mode) {
     //         Otherwise, we're only noticed by UCTOT or RxBRK!
     // change: don't care, we do not use these interrupts
     USC1(EMSUART_UART) = 0; // reset config first
-    // USC1(EMSUART_UART) = (0x7F << UCFFT) | (0x04 << UCTOT) | (1 << UCTOE); // enable interupts
+    // USC1(EMSUART_UART) = (0x7F << UCFFT) | (0x01 << UCTOT) | (1 << UCTOE); // enable interupts
 
     // set interrupts for triggers
     USIC(EMSUART_UART) = 0xFFFF; // clear all interupts
@@ -204,6 +177,7 @@ void ICACHE_FLASH_ATTR EMSuart::start(uint8_t tx_mode) {
     ETS_UART_INTR_ATTACH(emsuart_rx_intr_handler, nullptr);
     ETS_UART_INTR_ENABLE();
     drop_next_rx = true;
+    // LOG_INFO(F("UART service for Rx/Tx started"));
 
     // for sending with large delay in EMS+ mode we use a timer interrupt
     timer1_attachInterrupt(emsuart_tx_timer_intr_handler); // Add ISR Function
@@ -238,25 +212,18 @@ void ICACHE_FLASH_ATTR EMSuart::restart() {
  * Which is a 11-bit set of zero's (11 cycles)
  */
 void ICACHE_FLASH_ATTR EMSuart::tx_brk() {
-    // must make sure Tx FIFO is empty
-    while (((USS(EMSUART_UART) >> USTXC) & 0xFF))
-        ;
 
-    // do not clear buffers to get a echo back
-    // tmp = ((1 << UCRXRST) | (1 << UCTXRST)); // bit mask
-    // USC0(EMSUART_UART) |= (tmp);             // set bits
-    // USC0(EMSUART_UART) &= ~(tmp);            // clear bits
+    // make sure Tx FIFO is empty
+    while (((USS(EMSUART_UART) >> USTXC) & 0xFF)) {
+    }
 
     // To create a 11-bit <BRK> we set TXD_BRK bit so the break signal will
     // automatically be sent when the tx fifo is empty
     ETS_UART_INTR_DISABLE();
     USC0(EMSUART_UART) |= (1 << UCBRK); // set bit
 
-    if (tx_mode_ == EMS_TXMODE_EMSPLUS) {           // EMS+ mode
-        delayMicroseconds(EMSUART_TX_BRK_WAIT);     // 2070
-    } else if (tx_mode_ == EMS_TXMODE_HT3) {        // junkers mode
-        delayMicroseconds(EMSUART_TX_BRK_WAIT_HT3); // 1144
-    }
+    // also for EMS+ there is no need to wait longer, we are finished and can free the bus. 
+    delayMicroseconds(EMSUART_TX_WAIT_BRK);  // 1144
 
     USC0(EMSUART_UART) &= ~(1 << UCBRK); // clear BRK bit
     ETS_UART_INTR_ENABLE();
@@ -269,19 +236,38 @@ void ICACHE_FLASH_ATTR EMSuart::tx_brk() {
 void EMSuart::send_poll(uint8_t data) {
     // reset tx-brk, just in case it is accidentally set
     USC0(EMSUART_UART) &= ~(1 << UCBRK);
-    if (tx_mode_ > 5) { // timer controlled modes
+
+    if (tx_mode_ >= 5) { // timer controlled modes
         USF(EMSUART_UART) = data;
         emsTxBufIdx       = 0;
         emsTxBufLen       = 1;
         timer1_write(emsTxWait);
-    } else if ((tx_mode_ == EMS_TXMODE_NEW) || (tx_mode_ == 5)) { // hardware controlled modes
+    } else if (tx_mode_ == EMS_TXMODE_NEW) { // hardware controlled modes
         USF(EMSUART_UART) = data;
-        USC0(EMSUART_UART) |= (1 << UCBRK); // send <BRK> at the end
-    } else {                                // software controlled modes
-        // EMS1.0, EMS+ and HT3
+        USC0(EMSUART_UART) |= (1 << UCBRK); // brk after sendout
+    } else if (tx_mode_ == EMS_TXMODE_HT3) {
         USF(EMSUART_UART) = data;
-        delayMicroseconds(EMSUART_TX_BRK_WAIT);
+        delayMicroseconds(EMSUART_TX_WAIT_HT3);
         tx_brk(); // send <BRK>
+    } else if (tx_mode_ == EMS_TXMODE_EMSPLUS) {
+        USF(EMSUART_UART) = data;
+        delayMicroseconds(EMSUART_TX_WAIT_PLUS);
+        tx_brk(); // send <BRK>
+    } else { // EMS1.0, same logic as in transmit
+        ETS_UART_INTR_DISABLE();
+        volatile uint8_t _usrxc = (USS(EMSUART_UART) >> USRXC) & 0xFF;
+        USF(EMSUART_UART)       = data;
+        uint8_t timeoutcnt      = EMSUART_TX_TIMEOUT;
+        while ((((USS(EMSUART_UART) >> USRXC) & 0xFF) == _usrxc) && (--timeoutcnt > 0)) {
+            delayMicroseconds(EMSUART_TX_BUSY_WAIT); // burn CPU cycles...
+        }
+        USC0(EMSUART_UART) |= (1 << UCBRK); // set <BRK>
+        timeoutcnt = EMSUART_TX_TIMEOUT;
+        while (!(USIR(EMSUART_UART) & (1 << UIBD)) && (--timeoutcnt > 0)) {
+            delayMicroseconds(EMSUART_TX_BUSY_WAIT);
+        }
+        USC0(EMSUART_UART) &= ~(1 << UCBRK); // clear <BRK>
+        ETS_UART_INTR_ENABLE();
     }
 }
 
@@ -291,24 +277,15 @@ void EMSuart::send_poll(uint8_t data) {
  * returns code, 0=success, 1=brk error, 2=watchdog timeout
  */
 uint16_t ICACHE_FLASH_ATTR EMSuart::transmit(uint8_t * buf, uint8_t len) {
-    if (len == 0 || len > EMS_MAXBUFFERSIZE) {
+    if (len == 0 || len >= EMS_MAXBUFFERSIZE) {
         return EMS_TX_STATUS_ERR; // nothing or to much to send
     }
-
-    /*
-#ifdef EMSESP_DEBUG
-    // LOG_INFO(F("[DEBUG] UART Response time: %d ms"), uuid::get_uptime() - emsRxTime);
-#endif
-    // if ((uuid::get_uptime() - emsRxTime) > EMS_RX_TO_TX_TIMEOUT)) { // send allowed within 20 ms
-    //      return EMS_TX_STATUS_ERR;
-    // }
-    */
-
+ 
     // reset tx-brk, just in case it is accidentally set
     USC0(EMSUART_UART) &= ~(1 << UCBRK);
 
     // timer controlled modes with extra delay
-    if (tx_mode_ > 5) {
+    if (tx_mode_ >= 5) {
         for (uint8_t i = 0; i < len; i++) {
             emsTxBuf[i] = buf[i];
         }
@@ -320,7 +297,7 @@ uint16_t ICACHE_FLASH_ATTR EMSuart::transmit(uint8_t * buf, uint8_t len) {
     }
 
     // new code from Michael. See https://github.com/proddy/EMS-ESP/issues/380
-    if (tx_mode_ >= EMS_TXMODE_NEW) { // tx_mode 4
+    if (tx_mode_ == EMS_TXMODE_NEW) { // tx_mode 4
         for (uint8_t i = 0; i < len; i++) {
             USF(EMSUART_UART) = buf[i];
         }
@@ -329,26 +306,24 @@ uint16_t ICACHE_FLASH_ATTR EMSuart::transmit(uint8_t * buf, uint8_t len) {
     }
 
     // EMS+ https://github.com/proddy/EMS-ESP/issues/23#
-    if (tx_mode_ == EMS_TXMODE_EMSPLUS) { // tx_mode 2, with extra tx delay for EMS+
+    if (tx_mode_ == EMS_TXMODE_EMSPLUS) { // With extra tx delay for EMS+
         for (uint8_t i = 0; i < len; i++) {
             USF(EMSUART_UART) = buf[i];
-            delayMicroseconds(EMSUART_TX_BRK_WAIT); // 2070
+            delayMicroseconds(EMSUART_TX_WAIT_PLUS); // 2070
         }
         tx_brk(); // send <BRK>
         return EMS_TX_STATUS_OK;
     }
 
     // Junkers logic by @philrich
-    if (tx_mode_ == EMS_TXMODE_HT3) { // tx_mode 3
+    if (tx_mode_ == EMS_TXMODE_HT3) {
         for (uint8_t i = 0; i < len; i++) {
             USF(EMSUART_UART) = buf[i];
-
             // just to be safe wait for tx fifo empty (still needed?)
-            while (((USS(EMSUART_UART) >> USTXC) & 0xff))
-                ;
-
+            while (((USS(EMSUART_UART) >> USTXC) & 0xff)) {
+            }
             // wait until bits are sent on wire
-            delayMicroseconds(EMSUART_TX_BRK_WAIT_HT3);
+            delayMicroseconds(EMSUART_TX_WAIT_HT3);
         }
         tx_brk(); // send <BRK>
         return EMS_TX_STATUS_OK;
@@ -382,15 +357,15 @@ uint16_t ICACHE_FLASH_ATTR EMSuart::transmit(uint8_t * buf, uint8_t len) {
     // disable rx interrupt
     // clear Rx status register, resetting the Rx FIFO and flush it
     ETS_UART_INTR_DISABLE();
-    // USC0(EMSUART_UART) |= (1 << UCRXRST); // reset uart rx fifo
     emsuart_flush_fifos();
 
     // send the bytes along the serial line
     for (uint8_t i = 0; i < len; i++) {
         volatile uint8_t _usrxc = (USS(EMSUART_UART) >> USRXC) & 0xFF;
+        uint8_t timeoutcnt      = EMSUART_TX_TIMEOUT;
         USF(EMSUART_UART)       = buf[i]; // send each Tx byte
-        // wait for echo from the busmaster
-        while (((USS(EMSUART_UART) >> USRXC) & 0xFF) == _usrxc) {
+        // wait for echo
+        while ((((USS(EMSUART_UART) >> USRXC) & 0xFF) == _usrxc) && (--timeoutcnt > 0)) {
             delayMicroseconds(EMSUART_TX_BUSY_WAIT); // burn CPU cycles...
         }
     }
@@ -402,12 +377,11 @@ uint16_t ICACHE_FLASH_ATTR EMSuart::transmit(uint8_t * buf, uint8_t len) {
     // neither bus collision nor timeout - send terminating BRK signal
     if (!(USIS(EMSUART_UART) & (1 << UIBD))) {
         // no bus collision - send terminating BRK signal
-        // USC0(EMSUART_UART) |= (1 << UCLBE) | (1 << UCBRK); // enable loopback & set <BRK>
         USC0(EMSUART_UART) |= (1 << UCBRK); // set <BRK>
-
+        uint8_t timeoutcnt = EMSUART_TX_TIMEOUT;
         // wait until BRK detected...
-        while (!(USIR(EMSUART_UART) & (1 << UIBD))) {
-            delayMicroseconds(EMSUART_TX_BIT_TIME);
+        while (!(USIR(EMSUART_UART) & (1 << UIBD)) && (--timeoutcnt > 0)) {
+            delayMicroseconds(EMSUART_TX_BUSY_WAIT);
         }
 
         USC0(EMSUART_UART) &= ~(1 << UCBRK); // clear <BRK>
diff --git a/src/uart/emsuart_esp8266.h b/src/uart/emsuart_esp8266.h
index 26ca2478c..0f6d7d1e7 100644
--- a/src/uart/emsuart_esp8266.h
+++ b/src/uart/emsuart_esp8266.h
@@ -42,13 +42,18 @@
 
 // LEGACY
 #define EMSUART_TX_BIT_TIME 104  // bit time @9600 baud
-#define EMSUART_TX_BRK_WAIT 2070 // the BRK from Boiler master is roughly 1.039ms, so accounting for hardware lag using around 2078 (for half-duplex) - 8 (lag)
+#define EMSUART_TX_WAIT_BRK (EMSUART_TX_BIT_TIME * 11) // 1144
 
 // EMS 1.0
 #define EMSUART_TX_BUSY_WAIT (EMSUART_TX_BIT_TIME / 8) // 13
+#define EMSUART_TX_TIMEOUT (22 * EMSUART_TX_BIT_TIME / EMSUART_TX_BUSY_WAIT) // 176
 
-// HT3/Junkers - Time to send one Byte (8 Bits, 1 Start Bit, 1 Stop Bit). The -8 is for lag compensation.
-#define EMSUART_TX_BRK_WAIT_HT3 (EMSUART_TX_BIT_TIME * 11) - 8 // 1136
+// HT3/Junkers - Time to send one Byte (8 Bits, 1 Start Bit, 1 Stop Bit) plus 7 bit delay. The -8 is for lag compensation.
+// since we use a faster processor the lag is negligible
+#define EMSUART_TX_WAIT_HT3 (EMSUART_TX_BIT_TIME * 17) // 1768
+
+// EMS+ - Time to send one Byte (8 Bits, 1 Start Bit, 1 Stop Bit) and delay of another Bytetime.
+#define EMSUART_TX_WAIT_PLUS (EMSUART_TX_BIT_TIME * 20) // 2080
 
 namespace emsesp {
 
@@ -72,8 +77,6 @@ class EMSuart {
     } EMSRxBuf_t;
 
   private:
-    // static constexpr uint32_t     EMS_RX_TO_TX_TIMEOUT = 20;
-    static uuid::log::Logger      logger_;
     static void ICACHE_RAM_ATTR   emsuart_rx_intr_handler(void * para);
     static void ICACHE_FLASH_ATTR emsuart_recvTask(os_event_t * events);
     static void ICACHE_FLASH_ATTR emsuart_flush_fifos();