DC 12V

This is exactly as described and worked perfectly the very first time I wired it up. Use case: I had a car audio amplifier under my rear hatch floorboard powering a subwoofer, I think it had far too many overheating cut-outs until it gave up. I replaced that with a larger amp to now power TWO subwoofers, one remained under the floor and the other is in the open area in the back. I installed a 12vdc brushless fan to blow on the underside of the amp, and when I first got everything running, I noticed the fan is a LOT louder than I had hoped, so I bought this temperature switch. I wired it up so that the power to the fan instead went to the temp switch, then the unit's switched leads supplied the (+) 12vdc to the fan. I changed the settings for this video to show what happens when setting "d" is at 2°F and the target temperature is 73°F ... The amp's temp slowly crept up to [Target]+[d] and the fan kicked on and I watched the temp drop to 72.8°F before the fan kicked off. I then let it cycle through one more time to 75°F, fan kicked on, temp continued to creep up to 75.2°F before starting to fall back down, to 72.8°F and fan turned off. That was proof enough that this thing does exactly what I intend, and I now have it set to kick on at 100°F and run until the temp probe reaches 94.9°F (target = 95° and d = 5). The only complaint I have is that the programming is a little convoluted. I did not explore any settings beyond Target, d, and mode = C (for cooling, opposite of H which is designed to switch on a heater to get temps up when the probe gets too cold). I will update this if the unit fails within the first year of use.

This thing is exactly what I was hoping it was. I installed it as a cooling fan thermostat for my pickup. Of course, the internal relay shouldn't be loaded with an 80 watt fan, so I needed an additional relay to set everything up correctly. It reads down to tenths of a degree. The lead for the temperature probe that came with it was plenty long enough to run from inside the cab on the driver's side to the opposite side of the radiator. I wired it up as a ground side switch to reduce wire counts on long runs. I've probably used 5 "automotive" adjustable electric thermostats in as many years, one of each brand I could find. This setup has so far outlasted 3 of them. Doesn't seem to be as sensitive to voltage fluctuations, has a digital readout, and cost less than $20. Of course, this isn't meant to run an automotive cooling fan, and doesn't have an input for the A/C fan like the others do, and requires more complex wiring. Anyways, can be set to run a heater (on when cold, off when hot), a cooler (on when hot, off when cold) adjustable delta T, adjustable trigger temperature (whole degrees), and a warning for too hot/cold (flashing display, no sound). Also, it retains settings when disconnected from power. Update: 6-15-18 Still going strong, and I’ve had absolutely 0 problems. Works much better than everything else I’ve tried, and I only have it zip tied to the bottom side of the dash. Plenty enough vibration resistance.

I use this to run some basic ventilation fans in an electrical closet and it works great. Hard to beat for the price.

I used this controller to replace a inaccurate refrigerator/freezer thermostat. The controller has all the features needed to achieve a perfect temperature. The differential is easily adjusted and my temperature has been perfectly within the 4 degree differential I set. The probe is very accurate for temperature readings. All settings and examples are included in the included user guide. Operation and wiring are simple. The price was very reasonable for such a quality product. I strongly recommend this controller!

This controller / meter controls a DIY solar hot water system. Two collectors, one regular 50 gallon hot water tank, an external heat exchanger and two 12 volt pumps. Purchased and installed two meters for redundancy in case one fails. Both meter controls both pumps. If one meter fails, the system will continue to function. One of the sensors arrived not working and the company quickly replaced it. Good seller. Very happy with these. Good flexibility, decent instructions, always know what is going on. One controller in the office and one by the water tank. Extended sensors as much as 70 feet with no loss of accuracy. I did not use shielded wire, and used 20 to 22 gauge wire (rigid) with no problems. I recommend this product.

Works great to monitor my generator enclosure.

UPDATE: After submitting the review below I was contacted by the company and offered a full refund or a new product. I took the new product which is now up and running. I hope it lasts longer than the first 2. It is easy to install and program, so it's worth a 3rd try. This unit seems to work fine for a very short period of time. 2 have failed in the past year. This last one only lasted a couple of months. They were installed in a greenhouse and was protected from water and the elements. Time to find something higher quality.

Had for about a month now.. So far so good.

i am using to regulate the temp in my lithium battery housing, these are in a space that will go down to below 0

Good instructions if you read schematics and understand basic electronics. (I you do not, don't buy this!) The output is for driving a relay coil or other simple LOW CURRENT circuit. Installed in a sheltered but unconditioned locker in a travel trailer, it has been running a water tank heater for months with no problems.