---
product_id: 148776197
title: "HiLetgo 2pcs W1209 with Case 12V DC Digital Temperature Controller Board Micro Digital Thermostat -50-110°C Electronic Temperature Temp Control Module Switch with 10A One-Channel Relay and Waterproof"
brand: "hiletgo"
price: "€ 13.60"
currency: EUR
in_stock: true
reviews_count: 9
category: "Hi Letgo"
url: https://www.desertcart.ie/products/148776197-hiletgo-2pcs-w1209-with-case-12v-dc-digital-temperature-controller
store_origin: IE
region: Ireland
---

# Waterproof sensor included <35mA ultra-low power draw ±0.1°C precision control HiLetgo 2pcs W1209 with Case 12V DC Digital Temperature Controller Board Micro Digital Thermostat -50-110°C Electronic Temperature Temp Control Module Switch with 10A One-Channel Relay and Waterproof

**Brand:** hiletgo
**Price:** € 13.60
**Availability:** ✅ In Stock

## Summary

> 🌡️ Master your climate, command your comfort.

## Quick Answers

- **What is this?** HiLetgo 2pcs W1209 with Case 12V DC Digital Temperature Controller Board Micro Digital Thermostat -50-110°C Electronic Temperature Temp Control Module Switch with 10A One-Channel Relay and Waterproof by hiletgo
- **How much does it cost?** € 13.60 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.ie](https://www.desertcart.ie/products/148776197-hiletgo-2pcs-w1209-with-case-12v-dc-digital-temperature-controller)

## Best For

- hiletgo enthusiasts

## Why This Product

- Trusted hiletgo brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Smart Memory Retention:** Never lose your settings—built-in EEPROM remembers your preferences even after power outages.
- • **Robust 10A Relay Output:** Handles high-power loads effortlessly, perfect for demanding HVAC or industrial applications.
- • **Versatile Temperature Range:** From -50°C to 110°C, this controller adapts to extreme environments with ease.
- • **Pinpoint Temperature Accuracy:** Control your environment with razor-sharp ±0.1°C precision for flawless results every time.
- • **User-Friendly Digital Interface:** Intuitive LED display and simple button navigation make setup and adjustments a breeze.

## Overview

The HiLetgo W1209 Digital Temperature Controller is a compact, reliable thermostat module featuring a high-precision ±0.1°C control range from -50°C to 110°C. Powered by an embedded MCU with EEPROM memory, it ensures stable performance and retains settings after power loss. Equipped with a waterproof NTC sensor and a robust 10A relay, it supports a variety of high-power devices. Its intuitive LED interface and low power consumption (<35mA) make it ideal for HVAC, aquarium, and industrial temperature regulation.

## Description

Specifications: Model: W1209 With Case Dimensions: 48.5 * 40mm Temperature Control mode: ON / OFF Temperature Range :-50 - 110 degree centigrade Resolution: When temperature is 0.1 degree, the resolution is -9.9~99.9, other temperature segment is 1 degree. Control Accuracy: 0.1 degree Hysteresis Accuracy: 0.1 degree Refresh Rate: 0.5s High Temperature Protection 0 - 110 degree centigrade Supply Voltage: DC 12V Static Current: Less than 35MA, attract current less than 65MA Output Voltage: DC 12V Output Power: 20A relay Measurement Input: NTC (10K 0.5%) Waterproof Sensor Environmental Requirements: -10 - 60 degree centigrade; Humidity 20% - 85% Instructions for use: Connect the power supply and equipment, the measuring temperature is displayed, press the "SET" button, press " + or - " to set the desired temperature (long press " + or - " to quickly increase or decrease), press "SET" to confirm the setting and return, controller automatically performs the relay ON/OFF. the thermostat output is 10A relay, meet a variety of high-power loads. LED Indicator: LED off indicates the relay off; Lighting, indicates the relay is closed. Digital LED Tubes: "LL" indicates sensor open, "HH" indicates overrange, the relay will be forcibly disconnected; "---" indicates high temperature alarm Long press the "SET" button to enter the main menu settings, press " + or - " to switching between P0-P6, then long press "SET" or 10 seconds without keystrokes to confirm the setting and return. Package Included: 2 * W1209 12V DC Digital Temperature Controller Board With Case

Review: Air Conditioning Freezing Fixed! - While there are plenty of professional fixes for central AC that freezes up, sometimes it's just a combination bad duct airflow, low outside temp, and/or too low thermostat set. Obviously you should make sure you aren't low on refrigerant or the air filter is dirty, but if you have old ducting or a miss-sized unit, it just happens sometimes (especially fall and spring). If your wallet doesn't mind the thousands of dollars to get a new AC installed or otherwise remedied, skip this. For the rest of us, this little gem you just provide it 12V (find an old wall wart, or buy one for a few bucks), cut one of the signal wires from the furnace to the AC (usually 2 of them, carrying low voltage AC, doesn't matter which one you cut), strip the ends on both sides of the cut and put them into the two relay legs (K0 K1), and then tape the temp probe to the copper coolant-in line. Set the setpoint to somewhere a little above freezing (5C or so), set P0 to "C" for cooling, and then set P5 (restart time) to 5 minutes. Now, if the line approaches freezing, it will cut out the AC unit outside while the furnace/air-handler fan still blows air over the too-cold coils warming them up. The restart delay prevents short-cycling the AC. Cheap, easy, works. Will mask a dirty air filter, but you're changing that on a regular schedule, right?
Review: Cheap, effective, no instructions - I purchased this product for a little side project. I wanted to add a 12v fan to cool the charging transformer in a battery backup when it is charging on commercial power, but didn't want the fan to run 24x7. The UPS is no longer charging the small 7AH 12V batteries, but rather two 90AH 12V batteries. Installation of the device in the UPS case was pretty simple, but wiring and configuration was a different challenge since this product comes with absolutely no documentation. Keep in mind that this unit only deals with Celsius. If you want to know Fahrenheit, you'll need to convert it. Fortunately, some other reviews here have links to instructions and wiring diagrams. To wire it for 12V power to the controller board **AND** to the load device (fan in my case), do the following: 1. Connect the 12V power source to the +12V terminal 2. Run a short jumper wire from the +12V terminal to the K1 terminal, tighten down both +12V and K1 terminals. 3. On the 12V device, (fan in my case), connect the positive power wire to the K0 terminal and tighten the terminal 4. On the 12V device, (fan in my case), connect the negative return wire to the GND terminal. Also connect the negative return wire from the main power source to the GND terminal. Tighten down the terminal. To program the device for running a **cooling** fan like I did, do the following: 1. Short press "SET" button one quick time and set the desired "turn off" temperature with the "+ or -" buttons. This is the temperature that your fan will turn off once reached. Once you have your "off" temperature selected, press the "SET" button again. This should get you going. If you set the temperature to 30C, the default swing temperature is 2C. This means that the temperature probe must get to 32C before the fan will turn on. The fan will run until the thermal probe drops back to 30C, then shut off. If you want to change the default swing temperature from 2C, do the following: 1. Long press "SET" button until P0 shows on the screen. Press the + button until P1 is displayed. Short press "SET" button to modify that value. You should see "2" which is the current default setting. Press "+ or -" until the desired temperature is reached, then short press "SET" button again to set the new value. If the main "off" temperature is set to 30C like the above example, and you set P1 to 10, then the thermal probe would have to get to 40C before the fan kicks on. The fan would then run until the thermal probe reaches 30C before shutting off.

## Features

- 100% complete machine patch, wave soldering, stable performance, good consistency.
- Embedded CPU chip (MCU), more intelligent, lower power consumption.
- Automatic power set memory (MCU built-in EEPROM memory unit).
- Control accuracy of 0.1 degrees Celsius. Have been tested for stability, consistency and reliability.
- Tips: - long press set to get menu, starts at P0 - press +/- to get next P-parameter - press set to choose that parameter - press +/- to select the value you want for that parameter - press set to accept it - long press +/- = reset to default - power-out does reset to default - default temp set is 34.5C

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B07VDRGK9F |
| Batteries required | No |
| Best Sellers Rank | #35,621 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #61 in Temperature Controllers |
| Customer Reviews | 4.2 4.2 out of 5 stars (966) |
| Item Weight | 3.2 ounces |
| Item model number | 3-01-1310 |
| Manufacturer | HiLetgo |
| Product Dimensions | 1.91 x 1.57 x 1.91 inches |

## Product Details

- **Brand:** HiLetgo
- **Color:** With Case
- **Display Type:** LED
- **Item Weight:** 0.09 Kilograms
- **Voltage:** 12 Volts

## Images

![HiLetgo 2pcs W1209 with Case 12V DC Digital Temperature Controller Board Micro Digital Thermostat -50-110°C Electronic Temperature Temp Control Module Switch with 10A One-Channel Relay and Waterproof - Image 1](https://m.media-amazon.com/images/I/61zhEBHUK+L.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Air Conditioning Freezing Fixed!
*by J***S on October 3, 2025*

While there are plenty of professional fixes for central AC that freezes up, sometimes it's just a combination bad duct airflow, low outside temp, and/or too low thermostat set. Obviously you should make sure you aren't low on refrigerant or the air filter is dirty, but if you have old ducting or a miss-sized unit, it just happens sometimes (especially fall and spring). If your wallet doesn't mind the thousands of dollars to get a new AC installed or otherwise remedied, skip this. For the rest of us, this little gem you just provide it 12V (find an old wall wart, or buy one for a few bucks), cut one of the signal wires from the furnace to the AC (usually 2 of them, carrying low voltage AC, doesn't matter which one you cut), strip the ends on both sides of the cut and put them into the two relay legs (K0 K1), and then tape the temp probe to the copper coolant-in line. Set the setpoint to somewhere a little above freezing (5C or so), set P0 to "C" for cooling, and then set P5 (restart time) to 5 minutes. Now, if the line approaches freezing, it will cut out the AC unit outside while the furnace/air-handler fan still blows air over the too-cold coils warming them up. The restart delay prevents short-cycling the AC. Cheap, easy, works. Will mask a dirty air filter, but you're changing that on a regular schedule, right?

### ⭐⭐⭐⭐ Cheap, effective, no instructions
*by Z***X on March 6, 2019*

I purchased this product for a little side project. I wanted to add a 12v fan to cool the charging transformer in a battery backup when it is charging on commercial power, but didn't want the fan to run 24x7. The UPS is no longer charging the small 7AH 12V batteries, but rather two 90AH 12V batteries. Installation of the device in the UPS case was pretty simple, but wiring and configuration was a different challenge since this product comes with absolutely no documentation. Keep in mind that this unit only deals with Celsius. If you want to know Fahrenheit, you'll need to convert it. Fortunately, some other reviews here have links to instructions and wiring diagrams. To wire it for 12V power to the controller board **AND** to the load device (fan in my case), do the following: 1. Connect the 12V power source to the +12V terminal 2. Run a short jumper wire from the +12V terminal to the K1 terminal, tighten down both +12V and K1 terminals. 3. On the 12V device, (fan in my case), connect the positive power wire to the K0 terminal and tighten the terminal 4. On the 12V device, (fan in my case), connect the negative return wire to the GND terminal. Also connect the negative return wire from the main power source to the GND terminal. Tighten down the terminal. To program the device for running a **cooling** fan like I did, do the following: 1. Short press "SET" button one quick time and set the desired "turn off" temperature with the "+ or -" buttons. This is the temperature that your fan will turn off once reached. Once you have your "off" temperature selected, press the "SET" button again. This should get you going. If you set the temperature to 30C, the default swing temperature is 2C. This means that the temperature probe must get to 32C before the fan will turn on. The fan will run until the thermal probe drops back to 30C, then shut off. If you want to change the default swing temperature from 2C, do the following: 1. Long press "SET" button until P0 shows on the screen. Press the + button until P1 is displayed. Short press "SET" button to modify that value. You should see "2" which is the current default setting. Press "+ or -" until the desired temperature is reached, then short press "SET" button again to set the new value. If the main "off" temperature is set to 30C like the above example, and you set P1 to 10, then the thermal probe would have to get to 40C before the fan kicks on. The fan would then run until the thermal probe reaches 30C before shutting off.

### ⭐⭐⭐⭐⭐ Works as expected, great value
*by C***K on December 19, 2025*

These controllers work well and you can't beat the price. I'm using one to control a 20W silicone heater for an enclosed butter warmer. I keep the house cool in winter, and I got tired of mangling my toast when trying to spread cold butter. These don't have a parameter to switch from Centigrade to Fahrenheit display units like others do, but no big deal.

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*Product available on Desertcart Ireland*
*Store origin: IE*
*Last updated: 2026-03-13*