diff --git a/interface/src/mqtt/MqttSettingsForm.tsx b/interface/src/mqtt/MqttSettingsForm.tsx
index 26b0f3779..bb9e5a8d5 100644
--- a/interface/src/mqtt/MqttSettingsForm.tsx
+++ b/interface/src/mqtt/MqttSettingsForm.tsx
@@ -141,6 +141,16 @@ class MqttSettingsForm extends React.Component<MqttSettingsFormProps> {
         <Typography variant="h6" color="primary" >
           Formatting
         </Typography>
+        <BlockFormControlLabel
+          control={
+            <Checkbox
+              checked={data.nested_format}
+              onChange={handleValueChange('nested_format')}
+              value="nested_format"
+            />
+          }
+          label="Nested format (Thermostat & Mixer only)"
+        />
         <SelectValidator name="dallas_format"
           label="Dallas Sensor Payload Grouping"
           value={data.dallas_format}
diff --git a/interface/src/mqtt/types.ts b/interface/src/mqtt/types.ts
index bf9b09319..985fa36b4 100644
--- a/interface/src/mqtt/types.ts
+++ b/interface/src/mqtt/types.ts
@@ -40,4 +40,5 @@ export interface MqttSettings {
   mqtt_retain: boolean;
   ha_enabled: boolean;
   ha_climate_format: number;
+  nested_format: boolean;
 }
diff --git a/lib/framework/MqttSettingsService.cpp b/lib/framework/MqttSettingsService.cpp
index bf1d764dc..80dc08600 100644
--- a/lib/framework/MqttSettingsService.cpp
+++ b/lib/framework/MqttSettingsService.cpp
@@ -181,6 +181,7 @@ void MqttSettings::read(MqttSettings & settings, JsonObject & root) {
     root["bool_format"]             = settings.bool_format;
     root["ha_climate_format"]       = settings.ha_climate_format;
     root["ha_enabled"]              = settings.ha_enabled;
+    root["nested_format"]           = settings.nested_format;
 }
 
 StateUpdateResult MqttSettings::update(JsonObject & root, MqttSettings & settings) {
@@ -211,6 +212,7 @@ StateUpdateResult MqttSettings::update(JsonObject & root, MqttSettings & setting
     newSettings.bool_format       = root["bool_format"] | EMSESP_DEFAULT_BOOL_FORMAT;
     newSettings.ha_climate_format = root["ha_climate_format"] | EMSESP_DEFAULT_HA_CLIMATE_FORMAT;
     newSettings.ha_enabled        = root["ha_enabled"] | EMSESP_DEFAULT_HA_ENABLED;
+    newSettings.nested_format     = root["nested_format"] | EMSESP_DEFAULT_NESTED_FORMAT;
 
     if (newSettings.mqtt_qos != settings.mqtt_qos) {
         emsesp::EMSESP::mqtt_.set_qos(newSettings.mqtt_qos);
@@ -222,6 +224,10 @@ StateUpdateResult MqttSettings::update(JsonObject & root, MqttSettings & setting
         changed = true;
     }
 
+    if (newSettings.nested_format != settings.nested_format) {
+        changed = true;
+    }
+
     if (newSettings.ha_climate_format != settings.ha_climate_format) {
         emsesp::EMSESP::mqtt_.ha_climate_format(newSettings.ha_climate_format);
         changed = true;
diff --git a/lib/framework/MqttSettingsService.h b/lib/framework/MqttSettingsService.h
index 2b7eb5cf4..bd39f7569 100644
--- a/lib/framework/MqttSettingsService.h
+++ b/lib/framework/MqttSettingsService.h
@@ -68,6 +68,7 @@ static String generateClientId() {
 #define EMSESP_DEFAULT_MQTT_RETAIN false
 #define EMSESP_DEFAULT_HA_ENABLED false
 #define EMSESP_DEFAULT_PUBLISH_TIME 10
+#define EMSESP_DEFAULT_NESTED_FORMAT true
 
 class MqttSettings {
   public:
@@ -102,6 +103,7 @@ class MqttSettings {
     uint8_t  bool_format;
     uint8_t  ha_climate_format;
     bool     ha_enabled;
+    bool     nested_format;
 
     static void              read(MqttSettings & settings, JsonObject & root);
     static StateUpdateResult update(JsonObject & root, MqttSettings & settings);
diff --git a/lib_standalone/ESP8266React.h b/lib_standalone/ESP8266React.h
index 31bc4c91d..07e949532 100644
--- a/lib_standalone/ESP8266React.h
+++ b/lib_standalone/ESP8266React.h
@@ -32,6 +32,7 @@ class DummySettings {
     bool        mqtt_retain       = false;
     bool        enabled           = true;
     uint8_t     dallas_format     = 1;
+    bool        nested_format     = true;
     uint8_t     ha_climate_format = 1;
     bool        ha_enabled        = true;
     std::string base              = "ems-esp";
diff --git a/src/devices/mixer.cpp b/src/devices/mixer.cpp
index da0f31338..c6956c938 100644
--- a/src/devices/mixer.cpp
+++ b/src/devices/mixer.cpp
@@ -149,7 +149,7 @@ void Mixer::process_IPMStatusMessage(std::shared_ptr<const Telegram> telegram) {
     // do we have a mixed circuit
     if (ismixed == 2) {
         has_update(telegram->read_value(flowTempHc_, 3)); // is * 10
-        has_update(telegram->read_value(status_, 2));   // valve status
+        has_update(telegram->read_value(status_, 2));     // valve status
     }
 
     has_update(telegram->read_bitvalue(pumpStatus_, 1, 0)); // pump is also in unmixed circuits
@@ -164,7 +164,7 @@ void Mixer::process_MMStatusMessage(std::shared_ptr<const Telegram> telegram) {
     // 0x21 is position 2. 0x20 is typically reserved for the WM10 switch module
     // see https://github.com/proddy/EMS-ESP/issues/270 and https://github.com/proddy/EMS-ESP/issues/386#issuecomment-629610918
 
-    has_update(telegram->read_value(flowTempHc_, 1));         // is * 10
+    has_update(telegram->read_value(flowTempHc_, 1));       // is * 10
     has_update(telegram->read_bitvalue(pumpStatus_, 3, 2)); // is 0 or 0x64 (100%), check only bit 2
     has_update(telegram->read_value(flowSetTemp_, 0));
     has_update(telegram->read_value(status_, 4)); // valve status -100 to 100
diff --git a/src/mqtt.cpp b/src/mqtt.cpp
index 8054a1834..39abf4bf4 100644
--- a/src/mqtt.cpp
+++ b/src/mqtt.cpp
@@ -39,6 +39,7 @@ uint8_t     Mqtt::dallas_format_;
 uint8_t     Mqtt::bool_format_;
 uint8_t     Mqtt::ha_climate_format_;
 bool        Mqtt::ha_enabled_;
+bool        Mqtt::nested_format_;
 
 std::deque<Mqtt::QueuedMqttMessage> Mqtt::mqtt_messages_;
 std::vector<Mqtt::MQTTSubFunction>  Mqtt::mqtt_subfunctions_;
@@ -512,6 +513,7 @@ void Mqtt::on_connect() {
         ha_climate_format_       = mqttSettings.ha_climate_format;
         dallas_format_           = mqttSettings.dallas_format;
         bool_format_             = mqttSettings.bool_format;
+        nested_format_           = mqttSettings.nested_format;
     });
 
     // send info topic appended with the version information as JSON
@@ -862,19 +864,10 @@ void Mqtt::publish_mqtt_ha_sensor(uint8_t                     type, // EMSdevice
         snprintf_P(topic, sizeof(topic), PSTR("homeassistant/binary_sensor/%s/%s/config"), mqtt_base_.c_str(), uniq.c_str()); // topic
 
         // how to render boolean
-        if (bool_format_ == BOOL_FORMAT_ONOFF) {
-            doc[F("payload_on")]  = FJSON("on");
-            doc[F("payload_off")] = FJSON("off");
-        } else if (bool_format_ == BOOL_FORMAT_ONOFF_CAP) {
-            doc[F("payload_on")]  = FJSON("ON");
-            doc[F("payload_off")] = FJSON("OFF");
-        } else if (bool_format_ == BOOL_FORMAT_TRUEFALSE) {
-            doc[F("payload_on")]  = true;
-            doc[F("payload_off")] = false;
-        } else {
-            doc[F("payload_on")]  = 1;
-            doc[F("payload_off")] = 0;
-        }
+        // HA only accepts String values
+        char result[10];
+        doc[F("payload_on")]  = Helpers::render_boolean(result, true);
+        doc[F("payload_off")] = Helpers::render_boolean(result, false);
     } else {
         // normal HA sensor, not a boolean one
         snprintf_P(topic, sizeof(topic), PSTR("homeassistant/sensor/%s/%s/config"), mqtt_base_.c_str(), uniq.c_str()); // topic
diff --git a/src/mqtt.h b/src/mqtt.h
index 079a7dbd1..faee4d9d6 100644
--- a/src/mqtt.h
+++ b/src/mqtt.h
@@ -156,6 +156,10 @@ class Mqtt {
         return bool_format_;
     }
 
+    static bool nested_format() {
+        return nested_format_;
+    }
+
     static bool ha_enabled() {
         return ha_enabled_;
     }
@@ -181,18 +185,9 @@ class Mqtt {
     }
 
     static bool is_empty() {
-         return mqtt_messages_.empty();
+        return mqtt_messages_.empty();
     }
 
-    /*
-    struct QueuedMqttMessage {
-        uint16_t                           id_;
-        std::shared_ptr<const MqttMessage> content_;
-        uint8_t                            retry_count_;
-        uint16_t                           packet_id_;
-    };
-    */
-
     struct QueuedMqttMessage {
         const uint16_t                           id_;
         const std::shared_ptr<const MqttMessage> content_;
@@ -270,6 +265,7 @@ class Mqtt {
     static uint8_t     bool_format_;
     static uint8_t     ha_climate_format_;
     static bool        ha_enabled_;
+    static bool        nested_format_;
 };
 
 } // namespace emsesp