diff --git a/CHANGELOG.md b/CHANGELOG.md
index 86c44d0f308f..f62791d8f401 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@ All notable changes to this project will be documented in this file.
 ### Fixed
 - Shutter invert (#19341, #19374)
 - Teleinfo power (#19381)
+- Fix crash in IRHVAC
 
 ### Removed
 
diff --git a/tasmota/include/i18n.h b/tasmota/include/i18n.h
index b7023774c99f..94819a7d0ce0 100644
--- a/tasmota/include/i18n.h
+++ b/tasmota/include/i18n.h
@@ -123,7 +123,7 @@
 #define D_JSON_MODEL "Model"
 #define D_JSON_MOISTURE "Moisture"
 #define D_JSON_MQTT_COUNT "MqttCount"
-#define D_JSON_NA "n/a"
+#define D_JSON_NULL "null"
 #define D_JSON_NO "No"
 #define D_JSON_NOISE "Noise"
 #define D_JSON_NONE "None"
diff --git a/tasmota/tasmota_xdrv_driver/xdrv_05_irremote_full.ino b/tasmota/tasmota_xdrv_driver/xdrv_05_irremote_full.ino
index e0671de1e712..55eb8e96599d 100644
--- a/tasmota/tasmota_xdrv_driver/xdrv_05_irremote_full.ino
+++ b/tasmota/tasmota_xdrv_driver/xdrv_05_irremote_full.ino
@@ -227,7 +227,7 @@ namespace {
   void addFloatToJson(JsonGeneratorObject& json, const char* key, float value, float noValueConstant = NAN) {
     if (!isnan(noValueConstant) && value == noValueConstant) {
       //The "no sensor value" may not be straightforward (e.g.-100.0), hence replacing with explicit n/a
-      json.add(key, PSTR(D_JSON_NA));
+      json.addStrRaw(key, PSTR(D_JSON_NULL));
       return;
     }
     char s[6];  // Range: -99.9 <> 999.9 should be fine for any sensible temperature value :)