VIVOSUN 48" x 20.75" Seedling Heat Mat and Digital Thermostat Combo Set, UL & MET-Certified Warm Hydroponic Heating Pad for Germination, Indoor Gardening, Greenhouse

If you are an impatient gardener like me, you will love this thing. It really speeds up the germination time. Some seeds they used to take a week or 10 days germinating about three or four days. it seems to distribute the heat evenly without making it too hot which I guess could be dangerous. It seems to be designed well. The cord thick enough, that I don’t worry about it causing a fire. So far, it looks like it will last and provide the expected reliability for many seasons to come. Good value for the money.

Update to my review—I received the new replacement unit today and the new thermostat is working. Amazon and Vivosun quickly resolved my issue and sent a replacement that took only two days to arrive. Thanks to both Companies for taking care of this! I’ve increased my original 3 star review to 5 stars!Testing it out—you set the thermostat to a temperature, I.e. 74 degrees (Fahrenheit) and insert the temperature probe into the soil or growing medium. If the probe is reading less than the desired temperature it will run the heating pad until the medium is heated to the temperature you want it.My new replacement unit shows all this in degrees Fahrenheit, and let’s you program the temperature in Fahrenheit. The first “defective” one only showed it in degrees Celsius and could only be set to temperatures in Celsius before displaying the Fahrenheit Temperature.The new heating pad, like the previous one works, no issues there. Keep I’m mind though it plugs into the thermostat, the thermostat does not set or regulate the temperature of the heating pad. The heating pad will be warmer than the temperature displayed on the thermostat—as the thermostat is only monitoring the temperature of the soil or growing medium. Once it reaches the set temperature it shuts off power to the heating pad.My older review from earlier this week dealing with the defective thermostat:I am in the process of returning the combination seedling heating pad and thermostat because the thermostat doesn’t work. The unit I received did not supply power to the heating pad. I had set up everything as per the instructions and kept an eye on it, noticing that the “heating” light never came on with the pad plugged in. So I took a non contact thermometer and checked the pad temperature—it was room temp and nothing more, then plugged in an outlet tester (in the photos) to check the thermostat plug in for the heating pad and there was nothing. I’m assuming it’s not wired correctly and contacted Vivosun’s support via email. I emailed them Sunday and have not heard anything back yet, so I decided to exchange the item through Amazon—which had a very easy and efficient way of handling the exchange—they are sending me a new one which I hope works correctly and I have to drop the defective one off at my nearest Kohl’s store customer service department to be sent back to Amazon.I’ll have to update this once I get the replacement unit and can better judge the thermostat. The heating pad works very well and I had to manually regulate the temperature to sprout my seeds. It seems very heavy duty for the wattage it works on and should last a few seasons. I know it’s offered separately from the combination set I had ordered.If it had worked right, the thermostat was easy to set to the temperature on and I like how the probe is designed. The only other complaint I had was that you have to set the temperature in Celsius—but it will display the temperature in Fahrenheit. Some conversion work needs to be done if you want to set it at 80 degrees F for tomatoes.Had it worked and controlled the heating pad, had Viviosun contacted me back with their advice on what to do (it’s rumored on Facebook they are not responding to emails possibly because of being located in China and not working due to current events), I would have given this a 5 star review and written how well it works. Hopefully I can post that review once I get a properly working replacement.

This seedling heat mat with thermostat has been a staple in my indoor gardening setup for the past three seed-starting seasons, and it’s performed flawlessly. It delivers steady, controlled warmth that helps boost germination rates and keeps seedlings happy—no issues, no hassle.Pros:✅ Consistent Heating – Ideal temp range for seed starting✅ Thermostat Works Great – Simple to set and monitor✅ Durable – Still going strong after multiple seasons✅ UL & MET Certified – Safe for indoor and greenhouse useCons:❌ None so far!Final Thoughts:If you're serious about germination success, this combo set is absolutely worth it. Plug it in, set your temp, and let it do its job—it’s reliable season after season.

Heats up nicely. Only thing is the ends don't heat up as well, so you have to stay mostly in the middle.

So far so good. I like that it comes with its own thermostat controller and it is easy to set what temp you want. When it reaches temp it turns off and cools down a bit. Then after (I think) a 5-10 degree drop it kicks back on. I’ve been using it nonstop for 2 weeks for my frog quarantine containers. I have the probe between the mat and the container. And I just placed the mat on top of a flipped baking sheet to help prevent any heat issue on my counter.One complaint is the when it turns itself on/off you can hear an audible click. But I think most on/off thermostats do that.

Why did you pick this product vs others?:Perfect for making yogurt around 99 degrees! I couldn’t find any reviews specifically about making yogurt, but I went ahead and gave this mat a try with the thermostat. I rigged up an ice chest with the mat on the bottom and the thermostat on a jar with some water to mimic a yogurt jar. All my other yogurt jars go in the cooler on a rack. This works incredibly well and the thermostat at least in my experience is quite accurate, as I compared it with a cooking thermometer that I also stuck in there. I am making low temperature longer ferments such as Dr. William Davis’s L-Reuteri yogurt and this enables me to make many jars at a time! I also cover the cooler with a blanket. And I live in hawaii so if your house is colder more insulating might be helpful but I haven’t topped out the heating potential of the mat so it should work fine for you too.