Temperature controller MH1210W ,Review and Complete manual guide

In my review I will describe my 3 year experience with the W1210W thermostat from Shenzenn Meihang (MH). In this article, you can read the pros and cons of the product, how to set it up and where to buy it.

Now I am describing my experience with the W1210W thermostat, I tested about 450 pieces of this product and only 1 did not work. 2 pieces have ceased to work for three years, the other 447 thermostats work very well. Read the pros and cons of this product

 Price and buy

Temperature controller can buy from Ebay or AliExpress, good price varies around about 8 usd and more  shipping included.Keep in mind that at low cost 8-10 usd sell thermometers  not temperature controllers with case, MH1210W is very cheap (but with good stable and accuracy).

If you need low cost  If you want an even cheaper temperature controller  recommend  XH-W1209 cost is 2-3 usd very cheap but  not have case (only PCB electronic circuit).

Similar model is with degrees of fahrenheit and support 110V  good for US market. For Europe (UK ,Germany etc) use 230V and degrees of celsius.

Here are the pros and cons of MH-1210W temperature controller:

Here is pros

  • Control accuracy is 0.1 °C it is a great advantage !
  • Small size and have clips in the panel
  • Easy instrument control  (explained later in post)
  • Owns all the main functions that need good thermostat hysteresis, calibration, delayed start, and other ..
  • Good reliability
  • Very good price

Here is cons

  • Chinese characters like the scheme are not good
  • On some temperature controllers muss set a temperature of + – 0.5C (need calibrate , but is easy step)

Review conclusion:

It is a good device  with a good price.You pay from 7-15 usd (even with shipping) and you will get a stable device that you can set to high accuracy.

The disadvantage is Chinese terminal markers, you may be mistaken when connecting electrical wires so read my manual below. Shenzen Meihanng does not sound credible but produces cheap and good thermostats.

My rating is positive before writing reviews I tried about 450 pieces of Mh1210W.

 The best use this MH1210W temperature controller is in the hatcheries ,incubator,animal care sensitive to the correct temperature. It is good in boilers for heating water or in refrigerators and freezers.


Detailed description of temperature controller MH1210W

Now I will describe thermostat and control , i will try to describe accurately.The device MH1210W includes five main components:

  1. The display is red, it shows three digits four.clearly shows the temperature value withe the one decimal place.
  2. Below the display are four buttons which control the thermostat MH1210W. First buton is “SET”  with next two arrows buttons are + and – are used for menu navigation increasing or decreasing values. The fourth button is on / off
  3. The display has two diodes one shows that the thermostat has activated the relay (your device is on) – this diode has called work. The second diode lights up when you set the thermostat, called SET.
  4. Do we involve green terminal two terminals 1-2 is  for the relay 1 and 2 ,   terminal 3-4 for power from 90-250V  AC current ,for probe is terminals 5-6(No matter on polarity) .
  5. The sensor for the temperature controller MH-1210W  is placed in 5-6 terminals. It is about 80 cm long with active iron end.Type of temperature sensor is clasic NTC 10K 0.5%  B3435 .

Complete Guide Manual  how to connect and set MH1210W device

In this manual, I will show you how to properly connect and set up a good temperature controller from China.

How to properly connect terminals ((Do not connect under electric current))

First, let me explain wiring on  my scheme:

how to plug wires in to temperature controller

 schematic alternate

My tips how to connect the temperature controller :

  • Power is AC 90-250V This means that the thermostat is suitable for both the US and Europe..The trasformer in controller  is stable is not overheating.
  • DONT not connect to 5-6 phase and null wire !! … BAD …mistake  temperature controller burn  !
  • To relay terminal connect only phase wire  (NOT phase  with  null wire =BAD  relay burn)
  • If your device has a high power consumption equal to or greater than 10 amperes, I recommend feeding it through a contactor or solid state relay.. You can also control 3 phase devices (although the thermostat has only one phase)
  •  You can put the temperature cotroller  the cabinet or any DIY idea.

Here is a practical video how to set the thermostat:

How to SET goal temperature :

Before setting the temperature, you need to program the thermostat MH1210W correctly here as manual:

Short press button SET you can set goal temperature.

Long press button SET is access to the temperature controller menu.

The up and down arrows are to select the temperature or move the menu.

I recommend this setup procedure:

First go to menu of temperature controller (long push SET but)

SET HC – Heating or Cooling 

HC - menu

 H is heating . the setting control temperature is 28°C slewing range (hysteresis) temperature is 2°C  . when the environment temperature > setting temperature (28 °C ), the relay will switch off and stop the output load; when lhe environment temperature setting temperature (28°C )- slewing range of temperature (hysteresis) ‘ 2°C

Heat seting

C is cooling the set temperature is 28°C and slewing range (hysteresis) is 2°C.  When the temperature rises to 28 + 2C (slewing range of temperature is 2°C) he relay will switch on and start output load,The relay switches off when the temperature drops to 28°C.

cool seting

CA- is the temperature correction You can set it -10°C to 10°C by 0.1°C this is This is a big advantage of the MH 1210W thermostat (Other devices only support 1°C  calibration steps, this may be inaccurate)

calibration of temperature controller

LS and HS  min a max SET temperature limit are not the temperature control parameter adjustment, change will reduce the temperature control range.-50°C and +110°C is default range.

high set temperature limit lowest set temperature limit


PU is  delayed start – (if the delayed start function doesn’t need set the delayed start (code PU) to 0).For example, if you set a delayed start of 1 so when the temperature reaches the set limit, the temperature controller starts to read for 1 minute then the relay switches on. Is good options for protect cooling compressor.

delay start

A7 is delayed turn of relay For example, if you set a delayed  turn off reley   1min so when the temperature reaches the set limit, the temperature controller starts to read for 1 minute then the relay switches OFF.

A7 relay off delay

d is hysteresis slewing range (hysteresis). It is a temperature difference if the thermostat does not have to activate the relay. For example, if I heat and I have 28 and d 3 degrees so when the temperature reaches 28°C, the thermostat shuts off the relay and turns it on at 25°C (28°C-3°C as hysteresis).

hysteresis gap or slewing range

Set goal temperature 

After have done this settings you can quick  touch four buton for exist from menu al changes is saved. Tempereture controller showing actual temperature .Now set goal temperature : quick touch SET butons and arows up and down Increase or decrease the temperature.

it is default temperature when you click to button SET ..LED light on.
it is default temperature when you click to button SET ..LED light on.

If you need help send mee  comment -I will try to help

 Other info tips and hacks:

MH1210W has temperature sensor probe NTC – B3435 .The temperature sensor can be extended from 80cm to XX meters, for example 25 meters, the temperature deviation eliminate in the correction CA. (I described it up in the tutorial-manual)

temperature controller MH12010WQuick test of functionality:

  • Set the temperature to 31°C
  • HC set H
  • D set 1°C(or 0.5°C)
  • PU set 0

You can catch end the thermostat probe by hand and  you will see how the temperature rises and when it reaches 31 degrees the working LED and the relays turn off.The relay switches on again until the temperature reaches 30°C…test is done.

Set the temperature quickly To reach the set temperature faster, hold down the arrow button, the target temperature will change rapidly.

If you need to calibrate it, use a certified thermometer (not a scrap)



Technical paramters MH 1210W temperature controller:

  • Operating voltage: 90-250V AC
  • Power consumption: less than equal 3W
  • Rated current: 10A
  • Measuring range:-50 °C  to 110 °C
  • Accuracy of measurement: +- 05°C (can calibrate)
  • Increment step by : 0.1°C
  • Setting range:-50 Celsius has 110 Celsius
  • Temperature sensor: NTC 25 degrees Celsius
  • Output load: 10A / 220V AC
  • Operating temperature:-20 has 70 Celsius
  • Humidity: 90% non-condensing
  • The product size: approx. 8.5 x 7.5 x 3.45 cm / 3.34 x 2.95 x 1.35″

Package content:

1x temperature controller MH1210W

1 x temperature probe NTC 10K sensor
1x Englisch /Chinese manual


36 thoughts on “Temperature controller MH1210W ,Review and Complete manual guide”

  1. hi, first of all thank you for this informations. i have a mh1210w and i think i have locked parameters by mistake. and i can’t return to default settings. what should i do? yours respectfully

  2. Everything is addressed except one very important factor: backup for parameters. If I want to use this to keep something from freezing, I can set heat to come on at 35 degrees F and off at 40. But if there is power interruption, then it appears from manual, that parameters will go back to default of -50. So then I have no protection from freezing, and my product is destroyed, if there is power failure? What is the purpose of a controller with no battery backup?

    1. It will not loose your setting in case of power outage. It will not go back to factory default.
      I have set the parameters and unplugged the el power supply. Then I have plugged it back to el power and my set parameters that I have input, were all there. (So, nothing to worry about. I just tested it several times).

  3. hi,
    how to use this controller for my Infant baby wamer.? i am from India and a pediatrician. i am sick of using Indian make warmers which break down every month and fed up the low quality of warmers and the probes used and high cost of the servicing personnel.
    The heater element on the warmer is 650 watts and can i connect this controller to control the temperature.
    i am a doctor not a electronics or electrical engineer,but i can learn the basics and do something about my problem with help from people like you.

    i liked your video and thanks. keep up the good work

    1. For baby warmer you MUST NOT use a controller with AC 90-250V power supply voltage. The matter is that the MH1210W temperature controller does not have a transformer inside, it is just a step down converter. That means the dangerous high voltage could be present on temperature probe (sensor) line and the safety of your baby will depend on sensor wiring insulation quality ONLY! Please don’t take such a risk and use controller with 12V DC power supply. Good luck!

  4. Hi,
    Is it possible mine doesn’t have the “D” option? So it starts to cold down when the temp goes 2 degrees higher than the goal.

  5. I am trying to use a MH1210A. The model fed with 12V. The reason for choosing this model was that my interest was to use DC at low voltage. I would like to control a peltier module (TEC1-12706). I am using a transformer that feeds, then, with 12 V DC providing 0.5 A. The problem that I am finding is that the peltier does not work. I don’t think that the power is insuficient because if I connect directly the peltier to the transformer it works in the sense that one side gets cooler and the other warmer. I would appreciate if you could give me some hint. Yours,


    1. Hi relay is only for switching plus 12 cable split wire by schematic .. from 12V source to relay contact 1 and plus from peltier from relay contatn 2 , minus conect directly – to -.

      I temperature controller not switching
      SET HC desire mod H heat C cooling
      P7 And PT 0 (Timer)
      d Hysterezy 1

  6. Hi Ivan,
    My controller arrived locked and I don’t know how to unlock it to change settings. I enter the menus but I cannot change anything, just the aiming temperature.

    Do you know how to unlock it?

    PS: it also came with the wrong manual, so it is really difficult to find any information.

    1. Hi marcus MH1210W not have lock but of course exist similar temperature controlers with lock check back side near by power terminal , maybe have lock dip switches witch can unlock .

  7. Hello.
    I locked my device by mistake – OFF flashes – and can not exit. What is the procedure to perform?
    This text is a Google translation, I’m French

  8. Hi there, My controller has switched from oC to oF, can’t seem to find how to change it back, any ideas?
    Thanks in advance.

    1. LLL means probe not connected …maybe have bad probe please check sensor terminals
      on some types temperature controller LLL means out of temperature range

  9. Dear Ivan!
    My question is: will be there any problem , if I change the 230V plug, and phase and null lines will be replaced?
    I mean, in my equipment: 1 is phase, and 2 is null, for power 230V. Is there a problem if I change them? 2 is phase, and 1 is null?
    Thank you!

  10. Is there a galvanic seperation between power for the controller and relay output?
    I see some wiring diagrams depict that i can use seperate powers for controller and loads and not worry about L/N, but I cannot find any nspec about it.

  11. I have a question regarding setting for on and off: I want my freezer to go on at -10 deg C, and go off at -14 deg C. I tried but could not do. I need help.

  12. Poz kupio sam mh1210w na kojem je na engleskom uputstvo. Spajanja ne na kineskom.. i sad kad namjestim temp da se ugasi na 37.7 on se gasi ali kad se hladi pali ga tek na 35.7 c i nemogu nikako da ga naredim na odstupanje od 0.1c kao predhodni model koji sam uzeo mh1210w i na kojem sam bez problema i za cas naredio..i zadovoljan sam

  13. Hi. I do not know what happened that I did not turn on the work indicator and I programmed it but it does not activate. I even tighten the s and just turn on the s LED, not the work one. help. Thank you.

    1. Maybe device fail , most pelope switch valueas H and C (switch and cooling ) after this temperature not work

  14. hell,o just connect terminal 3 and 4. and I had a short circuit. I do not know why. The voltage of my house is 220V. I had no problems same connection with etc200+ / etc512B

  15. Hi
    I’m trying to distill alcohol with my distillation device. I bought this dtc machine and connected it. Set the temp.to 75 degrees. The machine and dtc is working but no distilled outcome is coming out.

    1. hi fatma if you will heating set thist

      set tempeature 75
      in menu
      HC- set H
      d- set 5 (if going temperature under 70c relay switch on)

  16. Hello, I have the 12V version of this controller. So I have to connect the 12V power source to terminals 3 and 4. Question: can I control a 220V load by simply using terminals 1 and 2 as an open/close relay? Many thanks!

  17. Attachment

    Dear Ivan. I got thermostat but it has already relay 10A and i need 40A. Can i feed it through separate ssr and how?

  18. selam .ben bu cihazın diyelim ki 90 derecede durmaksızın çalışmasını istiyorum.bunun için ne yapmalıyım.teşekkürler.su damıtma cihazında alkol elde etmek için..
    What I want is to run the gadget say,at 90 degrees nonstop,what should I do for this?thank you.to get alcohol with air still.

  19. Buongiorno in refrigerazione impostando la funzione HC su C e d = 0.2 la temperatura su -19 il relè si eccita e porta alla temperatura di -19° poi si diseccita e quando la temperatura ha raggiunto i-10° si rieccita, il parametro d non rispetta i 2° di differenza . come è possibile? GRAZIE

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