diff --git a/CHANGELOG_LATEST.md b/CHANGELOG_LATEST.md
index 025954be5..a5e60640f 100644
--- a/CHANGELOG_LATEST.md
+++ b/CHANGELOG_LATEST.md
@@ -3,7 +3,7 @@
 ### Added
 - function keys in editor: cursor, del, home, end. F1=help, F2=show, and other shortcuts
 - SM100 pump working time and energy units
-- heating curve parameters for RC300
+- heating curve parameters for RC300 (fixed)
 - `wwonetime` for RC300 thermostat
 
 ### Fixed
diff --git a/src/devices/thermostat.cpp b/src/devices/thermostat.cpp
index fd19f6acb..17c1c1ab9 100644
--- a/src/devices/thermostat.cpp
+++ b/src/devices/thermostat.cpp
@@ -773,6 +773,16 @@ std::shared_ptr<Thermostat::HeatingCircuit> Thermostat::heating_circuit(std::sha
         }
     }
 
+    // not found, search heating_curve message types
+    if (hc_num == 0) {
+        for (uint8_t i = 0; i < curve_typeids.size(); i++) {
+            if (curve_typeids[i] == telegram->type_id) {
+                hc_num = i + 1;
+                break;
+            }
+        }
+    }
+
     // not found, search timer message types
     if (hc_num == 0) {
         for (uint8_t i = 0; i < timer_typeids.size(); i++) {
diff --git a/src/emsesp.cpp b/src/emsesp.cpp
index 896139bf4..88015b0f3 100644
--- a/src/emsesp.cpp
+++ b/src/emsesp.cpp
@@ -471,7 +471,7 @@ std::string EMSESP::pretty_telegram(std::shared_ptr<const Telegram> telegram) {
         type_name = read_flash_string(F("?"));
     }
 
-    if (telegram->dest & 0x80) {
+    if (telegram->operation == Telegram::Operation::RX_READ) {
         direction = read_flash_string(F("<-"));
     } else {
         direction = read_flash_string(F("->"));
diff --git a/src/mqtt.cpp b/src/mqtt.cpp
index 9419ede2d..9196b95e3 100644
--- a/src/mqtt.cpp
+++ b/src/mqtt.cpp
@@ -727,7 +727,7 @@ void Mqtt::register_mqtt_ha_binary_sensor(const __FlashStringHelper * name, cons
     snprintf_P(topic, sizeof(topic), PSTR("homeassistant/binary_sensor/ems-esp/%s/config"), entity);
 
     // queue MQTT publish
-    publish(topic, doc.as<JsonObject>());
+    publish_retain(topic, doc.as<JsonObject>(), true);
 }
 
 // HA config for a normal 'sensor' type
diff --git a/src/mqtt.h b/src/mqtt.h
index 1f49b5e69..41e2899f6 100644
--- a/src/mqtt.h
+++ b/src/mqtt.h
@@ -38,7 +38,7 @@
 
 using uuid::console::Shell;
 
-#define EMSESP_MAX_JSON_SIZE_HA_CONFIG 256 // for small HA config payloads
+#define EMSESP_MAX_JSON_SIZE_HA_CONFIG 384 // for small HA config payloads
 #define EMSESP_MAX_JSON_SIZE_SMALL 384     // for smaller json docs when using StaticJsonDocument
 #define EMSESP_MAX_JSON_SIZE_MEDIUM 768    // for medium json docs from ems devices, when using StaticJsonDocument
 #define EMSESP_MAX_JSON_SIZE_LARGE 1024    // for large json docs from ems devices, like boiler or thermostat data. Using StaticJsonDocument
diff --git a/src/telegram.cpp b/src/telegram.cpp
index 4fb9e78af..350621e08 100644
--- a/src/telegram.cpp
+++ b/src/telegram.cpp
@@ -159,9 +159,10 @@ void RxService::add(uint8_t * data, uint8_t length) {
     }
 
     // src, dest and offset are always in fixed positions
-    uint8_t src    = data[0] & 0x7F; // strip MSB (HT3 adds it)
-    uint8_t dest   = data[1] & 0x7F; // strip MSB, don't care if its read or write for processing
-    uint8_t offset = data[3];        // offset is always 4th byte
+    uint8_t src       = data[0] & 0x7F; // strip MSB (HT3 adds it)
+    uint8_t dest      = data[1] & 0x7F; // strip MSB, don't care if its read or write for processing
+    uint8_t offset    = data[3];        // offset is always 4th byte
+    uint8_t operation = (data[1] & 0x80) ? Telegram::Operation::RX_READ : Telegram::Operation::RX;
 
     uint16_t  type_id;
     uint8_t * message_data;   // where the message block starts
@@ -212,7 +213,7 @@ void RxService::add(uint8_t * data, uint8_t length) {
     src = EMSESP::check_master_device(src, type_id, true);
 
     // create the telegram
-    auto telegram = std::make_shared<Telegram>(Telegram::Operation::RX, src, dest, type_id, offset, message_data, message_length);
+    auto telegram = std::make_shared<Telegram>(operation, src, dest, type_id, offset, message_data, message_length);
 
     // check if queue is full, if so remove top item to make space
     if (rx_telegrams_.size() >= MAX_RX_TELEGRAMS) {
diff --git a/src/telegram.h b/src/telegram.h
index 52a71bd9d..e438d784a 100644
--- a/src/telegram.h
+++ b/src/telegram.h
@@ -74,6 +74,7 @@ class Telegram {
     enum Operation : uint8_t {
         NONE = 0,
         RX,
+        RX_READ,
         TX_RAW,
         TX_READ,
         TX_WRITE,