diff --git a/esphome/components/datetime/datetime_base.h b/esphome/components/datetime/datetime_base.h
index b7645f5539..b5f54ac96f 100644
--- a/esphome/components/datetime/datetime_base.h
+++ b/esphome/components/datetime/datetime_base.h
@@ -30,14 +30,12 @@ class DateTimeBase : public EntityBase {
 #endif
 };
 
-#ifdef USE_TIME
 class DateTimeStateTrigger : public Trigger<ESPTime> {
  public:
   explicit DateTimeStateTrigger(DateTimeBase *parent) {
     parent->add_on_state_callback([this, parent]() { this->trigger(parent->state_as_esptime()); });
   }
 };
-#endif
 
 }  // namespace datetime
 }  // namespace esphome
diff --git a/esphome/components/htu21d/htu21d.cpp b/esphome/components/htu21d/htu21d.cpp
index a7aae16f17..c5d91d3dd0 100644
--- a/esphome/components/htu21d/htu21d.cpp
+++ b/esphome/components/htu21d/htu21d.cpp
@@ -9,8 +9,8 @@ static const char *const TAG = "htu21d";
 
 static const uint8_t HTU21D_ADDRESS = 0x40;
 static const uint8_t HTU21D_REGISTER_RESET = 0xFE;
-static const uint8_t HTU21D_REGISTER_TEMPERATURE = 0xE3;
-static const uint8_t HTU21D_REGISTER_HUMIDITY = 0xE5;
+static const uint8_t HTU21D_REGISTER_TEMPERATURE = 0xF3;
+static const uint8_t HTU21D_REGISTER_HUMIDITY = 0xF5;
 static const uint8_t HTU21D_WRITERHT_REG_CMD = 0xE6; /**< Write RH/T User Register 1 */
 static const uint8_t HTU21D_REGISTER_STATUS = 0xE7;
 static const uint8_t HTU21D_WRITEHEATER_REG_CMD = 0x51; /**< Write Heater Control Register */
diff --git a/esphome/config_validation.py b/esphome/config_validation.py
index ebfedf2017..e2f0b835c9 100644
--- a/esphome/config_validation.py
+++ b/esphome/config_validation.py
@@ -244,6 +244,20 @@ RESERVED_IDS = [
     "uart0",
     "uart1",
     "uart2",
+    # ESP32 ROM functions
+    "crc16_be",
+    "crc16_le",
+    "crc32_be",
+    "crc32_le",
+    "crc8_be",
+    "crc8_le",
+    "dbg_state",
+    "debug_timer",
+    "one_bits",
+    "recv_packet",
+    "send_packet",
+    "check_pos",
+    "software_reset",
 ]