---
product_id: 56373979
title: "LM YN DC 12V Digital Thermostat Module -58℉ to 257℉ Fahrenheit Temp Display Temperature Controller Board with 20A Relay Waterproof Sensor Probe Dual LED Display Red Blue"
brand: "lm yn"
price: "R421"
currency: ZAR
in_stock: true
reviews_count: 8
category: "Lm Yn"
url: https://www.desertcart.co.za/products/56373979-lm-yn-dc-12v-digital-thermostat-module-58-to-257
store_origin: ZA
region: South Africa
---

# 20A high-load relay capacity Wide temp range -58℉ to 257℉ Dual LED display (Red + Blue) LM YN DC 12V Digital Thermostat Module -58℉ to 257℉ Fahrenheit Temp Display Temperature Controller Board with 20A Relay Waterproof Sensor Probe Dual LED Display Red Blue

**Brand:** lm yn
**Price:** R421
**Availability:** ✅ In Stock

## Summary

> 🌡️ Stay cool or heat up—control your environment like a pro!

## Quick Answers

- **What is this?** LM YN DC 12V Digital Thermostat Module -58℉ to 257℉ Fahrenheit Temp Display Temperature Controller Board with 20A Relay Waterproof Sensor Probe Dual LED Display Red Blue by lm yn
- **How much does it cost?** R421 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.za](https://www.desertcart.co.za/products/56373979-lm-yn-dc-12v-digital-thermostat-module-58-to-257)

## Best For

- lm yn enthusiasts

## Why This Product

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

## Key Features

- • **Dual-Color LED Display:** Instantly monitor temps with vibrant red and blue LEDs for clear day/night visibility.
- • **Powerful Relay Control:** Handles up to 20A load, perfect for heating or cooling devices without compromise.
- • **Smart Memory Retention:** Keeps your settings intact even after power interruptions—no need to reset.
- • **Customizable Parameters:** Fine-tune temperature spread, heating/cooling modes, and device run times for tailored performance.
- • **Precision at Your Fingertips:** Ultra-sensitive sensor with 0.1℉ resolution for exact temperature control.

## Overview

The DC 12V Digital Thermostat Module offers precise temperature control from -58℉ to 257℉ with a fast 0.5-second refresh rate. Featuring a dual red and blue LED display, a waterproof 1-meter NTC sensor, and a robust 20A relay, it’s engineered for reliable heating and cooling applications. Compact and durable, it retains settings after power loss and supports customizable parameters to optimize device performance, making it ideal for professional and DIY temperature management.

## Description

Product Name: High-precision Digital Temperature Control Device. Dual LED display. The display font color: Red + Blue. Temperature range: -58℉ to + 257℉. Resolution: temperature range -3.9℉ ~ 99.9 ℉ is 0.1℉, other temperature ranges 1 ℉ Temperature measurement accuracy: 1 ℉. Backlash accuracy: 0.1 ℉. Refresh rate: about 0.5S. Input Power: DC 12V. Measuring input: 1 meter long NTC (10K 0.5%) waterproof metal sensors. Relay Load: DC 14V 20A / AC 125V 20A. Humidity: 20% to 75%. Size: 46 * 40 * 16mm (L * W * H). Weight: 30g. Package Included: 1pcs Digital Thermostat Module

Review: Easy setup and works perfectly - Using this to control an exaust fan mounted to the lid of my DIY solar generator. It's programmed to kick the 80mm fan on once the temperature reaches 85⁰. I then programmed a 2⁰ "dead band" so it doesn't continue cycling on and off. I then tested it several times by just holding the temperature probe in my hand. The digital guage shows the temp climbing and as soon as it hits the setpoint the relay kicks on and the fan starts spinning. Really neat and well designed gadget for the price. I will most likely get a second one to control some silicone heating pads to keep the Lifepo4 battery above freezing for winter use. In this case the unit will control a relay to send power to the heating pads vs running them right off the controller like I did with the fan.
Review: Works great! - I am using this for a small greenhouse and it works great. This is what I used... From Bastrop Guardian review: =============================== Technical Specifications: ------------------------------- Controller Power: .05VDC to 12VDC Controller Maximum Amperage: 20 Amps Controlled Device Votage: "0 to 14VDC" and "0 to 125VAC" Refresh rate: Approximately 0.5S Seconds Controller Draw: 150mA to 0.01 amps Note: I use this in my RV with Lithium Batters (14.4 Volts) and "So Far" - No Problems =============================== Features: ------------------------------- Modes: Cooling and Heating LED Display: Red & Blue. Temperature Range: -58 to +257 Degrees Farenheit Resolution: -3.9 ~ 99.9 Degrees Farenheit Accuracy: 1 Degree Farenheit Backlash Accuracy: 0.1 Degree Farenheit Memory: Retains its Settings after a "Power Disconnect" =============================== Light Indications: ------------------------------- "Lights On" = Your Controlled Device is On "Lights Off" = Your Controlled Device is Off Trouble Codes (Will Automatically "Power Off"): 1 = Sensor Missing or Damanged 2 = High Temperature Protection 3 = Low Temperature Protection =============================== Connectors: GND = 12VDC Power "Ground" VCC = 12VDC Power "Hot" KO = To Device K1 = From Source Note: This Device "Closes" [Dead Switch] Connector K0 (to Device) and K1 (from Source) when Activated (Passes Current [or Ground] "from" K1 "to" K0 to) your Controlled Device. Recommendation: If you are using a Device that Requires more than 20 Amps (or maybe "always" Regardless of Device Amperage Need), you may want to Use a Relay between this Controller and your Device - Using this Controller to "Trigger" your Relay and using the Relay to Power your Device. I always use a Relay for "All" my VDC Devices. Relay: https://www.desertcart.com/gp/product/B000P61E36/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Relay Connector: https://www.desertcart.com/gp/product/B001B801W2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 =============================== Parameter Setting Instructions: ------------------------------- "Set" Button: This Button will Allow you to: A) Enter the Temperature Setting B) Enter the Six Different Parameter Settings (Below) ----------------------------------------------- Setting the Temperature and Parameter Settings: on the Screen you want to Set/Change: A) Use the "+" Button to Increase the Value of the Parameter B) Use the "-" Button to Decrease the Value of the Parameter C) Press the "Set" Button once you Achieve your Desired Parameter Setting to Set ------------------------------- Parameter "P0" (Default "C" [Cooling]) / Temperature Default: 60 Degrees Chooses between Heating or Cooling (H/C). Once the Temperature Probe senses the "Set Temperature", the Relay Turns Off your Controlled Device. Important: See Parameter "P1" Below. ------------------------------- Parameter "P1" - (Default "2 Degrees"): Sets the Temperature "spread" between turning on your Controlled Device on and turning it off. Example: A) The relay will turn Off your Controlled Device when it Reaches "Set Temperature" (Parameter "P0" above) B) When the Temperature reaches "Set Temperature Spread Degrees +/- the Temperature Setting (Parameter "P0" above [H/C])", it will turn on your Controlled Device. Note: Increasing the "Spread" can keep your Controlled Device from turning On and Off too Often. ------------------------------- Parameter "P2" (Default "0 Degrees"): Temperature correction. Adjusts the Temperature the Probe is sensing if it is not reading correctly. Recommendation: Leave it at Default unless you are Certain there is a Temperature Reading Variance. ------------------------------- Parameter "P3" (Default "Off"): Adjusts "How Many Minutes" your Controlled Device Stays On within the "Temperature Parameters" (Parameters "P0" + "P1" Above). Note 1: Your Controlled Device will Continue to "Stay Off". Press the "Set Button" to Reset. Note 2: Only Needed if you Determine your Controlled Device is Staying On too long. ------------------------------- Parameter "P4" (Default "Off"): Adjusts "How Many Minutes" your Controlled Device Stays Off within the "Temperature Parameters" (Parameters "P0" + "P1" Above). Note 1: Your Controlled Device will Continue to "Stay On". Press the "Set Button" Repeatedly to Reset. Note 2: Only Needed if you Determine your Controlled Device is Staying Off too long. ------------------------------- Parameter "P5" (Default "Off") A) "On" Locks your Chosen Parameter Settings. B) "Off" Unlocks your Chosen Parameter Settings for when you'd like to Update them.

## Features

- Upgrade Models. Digital display is modified to Fahrenheit temperature display (old section is Celsius display). Dual LED display, Red + Blue, Precise temperature control, high sensitivity, suitable for any occasion required temperature.
- Temperature range:-58℉ to + 257℉ ; Resolution: temperature range -3.9℉ ~ 99.9 ℉ is 0.1℉, other temperature ranges 1 ℉.
- Temperature measurement accuracy: 1 ℉. Backlash accuracy: 0.1 ℉. Refresh rate: about 0.5S. Input Power: DC 12V.
- Measuring input: 1 meter NTC (10K 0.5%) waterproof metal sensors.
- Relay Load: DC 14V 20A / AC 125V 20A. ( If the module works for a long time, it is recommended not to exceed 10A.)

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B076Y5BXD9 |
| Best Sellers Rank | #61,961 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #74 in Temperature Controllers |
| Brand Name | LM YN |
| Color | 'Red Blue' |
| Customer Reviews | 4.2 4.2 out of 5 stars (231) |
| Display Type | LED |
| Item Dimensions L x W x H | 1.81"L x 1.57"W x 0.63"H |
| Item Weight | 30 Grams |
| Manufacturer | LM YN |
| Material Type | Metal |
| UPC | 612957708276 |
| Unit Count | 1.0 Count |
| Voltage | 12 Volts |
| Warranty Description | 1 year |

## Product Details

- **Brand:** LM YN
- **Color:** 'Red Blue'
- **Material:** Metal
- **Product Dimensions:** 1.81"L x 1.57"W x 0.63"H
- **Voltage:** 12 Volts

## Images

![LM YN DC 12V Digital Thermostat Module -58℉ to 257℉ Fahrenheit Temp Display Temperature Controller Board with 20A Relay Waterproof Sensor Probe Dual LED Display Red Blue - Image 1](https://m.media-amazon.com/images/I/81fC6in0d2L.jpg)

## Questions & Answers

**Q: Can i set the hysteresis to .5°f? I am trying to make my incubator easier to use and this might be the ticket if I can can set it to hold tight temper**
A: I haven't tried it but the P1 setting allows for hysteresis settings. I use 2 degrees, but it might be possible to refine it.

**Q: Can the length of the wire for the temperature sensor be extended?**
A: I haven't tried it, but the sensing current is so low that doubling or tripling the length would not affect it noticeably.

**Q: 120v AC input 120v AC output?**
A: This requires  Input Power: DC 12V to runt the electronics but it can "switch AC or DC. And yes it can switch 120AC.  The unit is controlling a relay.

**Q: Im doing a car audio amp rack with a fan will this control the fan and come on when amp gets hot then shut off when cooled?**
A: According to your description, it can work.
Connect the cooling fan and the power supply for the fan between K0 and K1. Connect VCC and GND to DC12V to supply power to the module. Place the temperature control probe in the place where the temperature needs to be measured and set the temperature.
You can check the user manual first to learn more about it.
LM YN Digital Thermostat Module User Manual Download Link:
https://www.amazon.com/clouddrive/share/2erQJUA07h19hgz1mIik6kOeJZWPSZkNSfBaZtjWFaJ

## Customer Reviews

### ⭐⭐⭐⭐⭐ Easy setup and works perfectly
*by N***N on May 5, 2023*

Using this to control an exaust fan mounted to the lid of my DIY solar generator. It's programmed to kick the 80mm fan on once the temperature reaches 85⁰. I then programmed a 2⁰ "dead band" so it doesn't continue cycling on and off. I then tested it several times by just holding the temperature probe in my hand. The digital guage shows the temp climbing and as soon as it hits the setpoint the relay kicks on and the fan starts spinning. Really neat and well designed gadget for the price. I will most likely get a second one to control some silicone heating pads to keep the Lifepo4 battery above freezing for winter use. In this case the unit will control a relay to send power to the heating pads vs running them right off the controller like I did with the fan.

### ⭐⭐⭐⭐⭐ Works great!
*by E***O on May 18, 2021*

I am using this for a small greenhouse and it works great. This is what I used... From Bastrop Guardian review: =============================== Technical Specifications: ------------------------------- Controller Power: .05VDC to 12VDC Controller Maximum Amperage: 20 Amps Controlled Device Votage: "0 to 14VDC" and "0 to 125VAC" Refresh rate: Approximately 0.5S Seconds Controller Draw: 150mA to 0.01 amps Note: I use this in my RV with Lithium Batters (14.4 Volts) and "So Far" - No Problems =============================== Features: ------------------------------- Modes: Cooling and Heating LED Display: Red & Blue. Temperature Range: -58 to +257 Degrees Farenheit Resolution: -3.9 ~ 99.9 Degrees Farenheit Accuracy: 1 Degree Farenheit Backlash Accuracy: 0.1 Degree Farenheit Memory: Retains its Settings after a "Power Disconnect" =============================== Light Indications: ------------------------------- "Lights On" = Your Controlled Device is On "Lights Off" = Your Controlled Device is Off Trouble Codes (Will Automatically "Power Off"): 1 = Sensor Missing or Damanged 2 = High Temperature Protection 3 = Low Temperature Protection =============================== Connectors: GND = 12VDC Power "Ground" VCC = 12VDC Power "Hot" KO = To Device K1 = From Source Note: This Device "Closes" [Dead Switch] Connector K0 (to Device) and K1 (from Source) when Activated (Passes Current [or Ground] "from" K1 "to" K0 to) your Controlled Device. Recommendation: If you are using a Device that Requires more than 20 Amps (or maybe "always" Regardless of Device Amperage Need), you may want to Use a Relay between this Controller and your Device - Using this Controller to "Trigger" your Relay and using the Relay to Power your Device. I always use a Relay for "All" my VDC Devices. Relay: https://www.amazon.com/gp/product/B000P61E36/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Relay Connector: https://www.amazon.com/gp/product/B001B801W2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 =============================== Parameter Setting Instructions: ------------------------------- "Set" Button: This Button will Allow you to: A) Enter the Temperature Setting B) Enter the Six Different Parameter Settings (Below) ----------------------------------------------- Setting the Temperature and Parameter Settings: on the Screen you want to Set/Change: A) Use the "+" Button to Increase the Value of the Parameter B) Use the "-" Button to Decrease the Value of the Parameter C) Press the "Set" Button once you Achieve your Desired Parameter Setting to Set ------------------------------- Parameter "P0" (Default "C" [Cooling]) / Temperature Default: 60 Degrees Chooses between Heating or Cooling (H/C). Once the Temperature Probe senses the "Set Temperature", the Relay Turns Off your Controlled Device. Important: See Parameter "P1" Below. ------------------------------- Parameter "P1" - (Default "2 Degrees"): Sets the Temperature "spread" between turning on your Controlled Device on and turning it off. Example: A) The relay will turn Off your Controlled Device when it Reaches "Set Temperature" (Parameter "P0" above) B) When the Temperature reaches "Set Temperature Spread Degrees +/- the Temperature Setting (Parameter "P0" above [H/C])", it will turn on your Controlled Device. Note: Increasing the "Spread" can keep your Controlled Device from turning On and Off too Often. ------------------------------- Parameter "P2" (Default "0 Degrees"): Temperature correction. Adjusts the Temperature the Probe is sensing if it is not reading correctly. Recommendation: Leave it at Default unless you are Certain there is a Temperature Reading Variance. ------------------------------- Parameter "P3" (Default "Off"): Adjusts "How Many Minutes" your Controlled Device Stays On within the "Temperature Parameters" (Parameters "P0" + "P1" Above). Note 1: Your Controlled Device will Continue to "Stay Off". Press the "Set Button" to Reset. Note 2: Only Needed if you Determine your Controlled Device is Staying On too long. ------------------------------- Parameter "P4" (Default "Off"): Adjusts "How Many Minutes" your Controlled Device Stays Off within the "Temperature Parameters" (Parameters "P0" + "P1" Above). Note 1: Your Controlled Device will Continue to "Stay On". Press the "Set Button" Repeatedly to Reset. Note 2: Only Needed if you Determine your Controlled Device is Staying Off too long. ------------------------------- Parameter "P5" (Default "Off") A) "On" Locks your Chosen Parameter Settings. B) "Off" Unlocks your Chosen Parameter Settings for when you'd like to Update them.

### ⭐⭐⭐⭐ Excellent unit for the cost
*by J***S on January 23, 2018*

I have purchased 7 of these. 3 in operation currently, 2 spares, and 2 that I managed to short out somehow. I love that the load circuit can handle AC or DC, and that the read out operates on DC. Very handy in my off grid home. One unit senses temp on a thermal storage tank and controls a 120 vac circulator pump, the second senses my wood boiler temp and controls a 120 vac blower. The third controls a 12 vdc radiator fan and 12 vdc circulator pump. I did somehow short two of them out... pretty sure that was my fault. My only complaints are that they are not very easy to mount to anything and they do not include any schematics whatsoever. What you see on the images section of Amazon is all you get, which is fine as long as you are aware.

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*Product available on Desertcart South Africa*
*Store origin: ZA*
*Last updated: 2026-04-24*