WILLHI WH1436A 110V - 240V Digital Temperature Controller Thermostat Switch NTC 10K Sensor, Improved Version

I purchased this unit to assist me in operating a home built smoker. I operate two 400 watt heating elements with it. I've found the directions to be concise although somewhat confusing but once the high and low temperatures are set and the temperature probe is in place the unit operates perfectly.

If you're even considering an AC relay temperature controller, don't even think twice. Just buy the WH1436. You will not regret the purchase. I promise.Review updated 2017/05 to account for model revision (older WH1436 vs newer WH1436A).+ Heating and cooling mode (i.e. power supplied if temperature is below or above a threshold)+ Waterproof thermocouple included! (this is pretty hard to find on the cheap)+ regulates down to 0.1 degree window (high/low bounds for on/off)+ F and C units+ TONS of advanced options: e.g. temperature alarms and compressor safety timeouts+ 1.1kW continuous power rating (up from the 880W in the 2015 model that I bought)+/- mechanical relay click sound when device toggles state (the A model likely now uses a silent solid state relay)- Not a PID controller (more details below on why this could matter)- Upside down power connector (the A revision now uses a NEMA 15-5, which is great, but the plug is still upside down)There are a lot of temperature controllers and sous-vide devices on the market. Some have more or less features than others. Some require other parts, like thermocouples. Heck, at one point I was even considering building my own with a microcontroller, relay, and temp probe (and hours of testing and frustration). The WH1436 is what I've been waiting for and I'm so glad I held out! It's a compact, simple little device and has all the pieces you need for under $30! That's way cheaper than even I could have built one for. Other devices sell for many times this price, up to hundreds of dollars, and aren't nearly as flexible. See the  Anova , Dorkfoods , or  Johnson  for excellent overpriced examples.My target is sous-vide, but the WH1436 could also be used for cooling applications as well. Yes, the instruction manual is a bit overwhelming, but it is detailed and accurate. There are so many features if you really want to fiddle with things, but I found the defaults intelligently chosen and usable. One change I'd suggest is to lower the d parameter from 1.0 to 0.1 (the offset between the target temperature and the relay turning on). If you need help, search youtube for the videos from Bayite and you'll see detailed video instructions on how to use the device. If all else fails, just send the guy an email and he'll get back to you, or just post a question here, as others have done, and you'll see he replies quickly. Note, this paragraph was written based on the old software, the newer software seems to be even easier: set heating vs cooling mode, lower bound, and upper bound.The only legitimate complaint that you could make about this device is that it's not a PID controller. What this means is that it works only on instantaneous temperature measurements. A PID controller uses not just the current temperature, but also tracks the total power delivered (The I in PID), and the rate of change of the temperature (the D in PID), so that it can turn the heat/cooling on and off to keep the temperature exactly at the desired setpoint. This would manifest in behavior like the heat turning off prior to the desired setpoint because the PID controller knows that the temperature will continue to rise to hit the target. It's a more intelligent approach for control (and based on over hundred year old mathematical principles). The WH1436 doesn't have a PID controller, it's just instantaneous on/off based on the setpoint, so it's not as intelligent, but for slow moving temperature settings (like a big crock pot), it can still achieve excellent tight temperature control (my window sits with 1.5C). For the price, it's unbeatable. A PID controller would be a bit more expensive, as the logic is more complicated. What amazer me is that WILLHI did release a "PID" version last year that I bought (WHI1436PID). It wasn't actually a PID controller, but it did have some really neat parameters that would permit very tight temperature control (I got it down to 0.1-0.2C from my target). However, it seems like that model isn't sold anymore. I haven't purchased the updated model (WH1436A) yet, so I can't comment on how smart the newer software is, but if it permits bounding down to 0.1C/F, then that's about as tight as you can reliably get things with a consumer product.It is incredibly versatile because it just regulates an AC socket based on a temperature. I've used it for sous-vide with a crock pot, a rice cooker, and even a portable electric stove with a dutch oven on top. They all work perfectly and deliver fantastic results. At under $30, you can even buy a few of these and set them up to have multiple baths and temperatures going at the same time. Do beef in one, potatoes in another, and vegetables in a third. Things could always be cheaper, but this is a fair price point. These temperature controllers are not particularly expensive pieces of electronics, and I'm glad we finally have an inexpensive option that gets it all right. So long as what you're trying to power is under 1kW, buy this, you'll love it. Combined with an equally affordably priced  vacuum sealer  and  manual slow cooker , you can sous-vide like a pro for under $100. AnovaDorkfoodsJohnsonvacuum sealermanual slow cooker

I am using this item to control the temperature in a confined space for brewing, spore growth and seed starting and it works very well indeed. It comes with good instructions and there is access to a video on u-tube if they are inadequate. I have been able to maintain a good solid temperature range and am very pleased with this product.

I bought this for a small greenhouse heater control, but I'm testing it out with an oil-filled radiator in the house. Setup was easy. Construction seems solid. Temperature control has been great. It is designed to control either a heater or an air conditioner. I have it set to come on at 66 degrees and go off at 70 degrees. I also have a nearby thermometer at about the same height. Temperature readout is closely consistent with my AccuRite thermometer/humidity sensor, and the heater is appropriately turned on and off. The built-in temperature control on the heater was never accurate and always made an annoying click. At night, that click would wake me up. But, with this temperature controller, the heater makes no sound at all. It's great. It is also possible to adjust the controller thermometer reading if you find it to be off. I haven't had to do that. I love the sensor wire as it allows me to put the thermometer sensor at person height or plant height, unlike other options where the sensor is attached directly to the controller. I've only been using it for a couple of days, so I don't know about durability, but so far, it's great. I might get a couple more for other locations. Recommended!Nov 29, 2020: Still using this in my study and am delighted with it. It reliably turns a small oil-filled radiator on and off to maintain an even temperature. The unit is rated for up to 1100 watts so it is important to stay within that range. I had intended to use this in my small greenhouse but it works so well in my study that I have kept it there and bought a second one for the greenhouse. It is also working great there. To not exceed the power rating in the greenhouse, I have 2 heaters: one 400 watt heater set on a timer to come on in the evening, and another 1000 watt heater hooked up to this temperature controller. Even in the low 30's my greenhouse stays within the desired range. Both of my units have worked flawlessly.One improvement would be the option to turn off the display. At night in a dark room it can be quite prominent. I can always cover it with a heavy cloth or small cardboard box, but it would be nice if I didn't need to. That is the only thing holding me back from getting a third unit for my bedroom, which I might get anyway and just deal with it.3/2/2021: I now have 3 of these units. All have worked flawlessly. The unit in the greenhouse would occasionally trip. This seemed to be due to a small 1000 watt ceramic heater which does have a higher current draw on startup. I turned that heater down to the 500 watt setting and no further issues. I also put one of these in my small bedroom. It seemed that I could never get the temperature in the room right, and I would find myself either too cold or too hot at night. I got one of these controllers, put the sensor at bed height and plugged in a small oil-filled heater. After some experimentation I found the perfect temperature for sleeping, and the controller silently keeps the temperature consistently even. It's great! I did need to lay a cloth over the display to block the light, but that was all. I marvel at how perfectly comfortable my rooms are now.

I use it to convert my 3.8 cf chest freezer into a fridge. Allows me to set the power on at 4c and off at -1c. Works flawlessly