ESP32 - Control Heating Element

This tutorial instructs you how to use ESP32 to control a Heating Element. Based on this tutorial, you will learn how to make a heating system in another tutorial.

Hardware Used In This Tutorial

1×ESP-WROOM-32 Dev Module
1×USB Cable Type-C
1×Heating Element
1×12V Power Adapter
1×(Optional) DC Power Jack
1×Jumper Wires
1×(Recommended) ESP32 Screw Terminal Adapter

Or you can buy the following sensor kits:

1×DIYables Sensor Kit (30 sensors/displays)
1×DIYables Sensor Kit (18 sensors/displays)
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Introduction to Heating Element


ESP32 Heating Element Pinout

Heating Element usually has two pins:

  • Positive (+) pin (red): needs to be connected to 12V of DC power supply
  • Negative (-) pin (black): needs to be connected to GND of DC power supply

How to Control Heating Element

If 12V Heating Element is powered by 12V power supply, it emits heat. To control a Heating Element, we need to use a relay in between ESP32 and Heating Element. ESP32 can control the Heating Element via the relay. If you do not know about relay (pinout, how it works, how to program ...), learn about relay in the ESP32 - Relay tutorial

Wiring Diagram

ESP32 Heating Element Wiring Diagram

This image is created using Fritzing. Click to enlarge image

If you're unfamiliar with how to supply power to the ESP32 and other components, you can find guidance in the following tutorial: How to Power ESP32.

ESP32 Code

The below code repeatedly turns the Heating Element ON in five seconds and OFF in five seconds,

/* * This ESP32 code is created by * * This ESP32 code is released in the public domain * * For more detail (instruction and wiring diagram), visit */ #define RELAY_PIN 16 // ESP32 pin GPIO16 connected to the heating element via the relay // the setup function runs once when you press reset or power the board void setup() { // initialize digital pin A5 as an output. pinMode(RELAY_PIN, OUTPUT); } // the loop function runs over and over again forever void loop() { digitalWrite(RELAY_PIN, HIGH); // turn on heating element 5 seconds delay(5000); digitalWrite(RELAY_PIN, LOW); // turn off heating element 5 seconds delay(5000); }

Quick Instructions

  • Connect ESP32 to PC via USB cable
  • Open Arduino IDE, select the right board and port
  • Copy the above code and paste it to Arduino IDE
  • Compile and upload code to ESP32 board by clicking Upload button on Arduino IDE
  • Check the Heating Element's temperature


Please be careful. It can burn you and your house. This is a serious topic, and we want you to be safe. If you’re NOT 100% sure what you are doing, do yourself a favor and don’t touch anything. Ask someone who knows! We do NOT take any responsibility for your safety.

Code Explanation

The above ESP32 code contains line-by-line explanation. Please read the comments in the code!

Video Tutorial

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