Thermacell Mosquito Repellent: Product Review
Review updated July 2, 2019
If you’re a mosquito magnet like me, you’re always looking for ways to keep the pesky critters at bay. Choices mostly involve covering yourself in smelly sprays or lighting smoky and smelly coils or candles. The Thermacell mosquito repellent “appliance” is neither of those.
What is the Thermacell Mosquito Repellant Appliance?
“Appliance” is a strange name but it’s hard to come up with something better. It’s a device that emits a repellant that keeps mosquitoes and black flies away. There’s no need to spray yourself and there’s hardly any odor. And yes, it works.
The original Thermacell mosquito repellent device (which is still available) was the 8″ by 3″ item shown in the photo at right.
Since then, the company has introduced a wide variety of device styles, from portable ones similar to the original, to lanterns (complete with lights) and torches, and unobtrusive appliances that are meant to stay outside on your balcony, patio or deck (those are my favorite option). There’s even a backpacker model that attaches to a camp fuel canister!
And the company continues to innovate. The Radius Zone Mosquito Repeller, Gen 2.0, lasts 40 hours on one refill, uses a rechargeable Li-ion battery that recharges in 5 hours and even has a shut-off timer (no more forgetting to turn it off and finding empty butane cartridges the next day!).
How Does the Thermacell Work?
All of the Thermacell appliances use a butane cartridge to heat up a small mat that’s soaked in mosquito repellent. Don’t worry – there are no open flames so it’s safe to use around fabric and children. As the mat warms, the repellent is released into the air.
Each appliance comes with one butane cartridge and three mats. Refills (both the butane cartridges and repellent mats) are easy to find (this is the refill pack I recommend).
To see the device in action, including how to install the mat and cartridges and my take on how best to use it, check out the video below.
Long-Lasting Butane Cartridge
The butane cartridge is screwed into the bottom of the appliance. Each cartridge lasts about 12 hours and you can see the amount of butane in the cartridge through a slit in the back of the appliance. It’s easy to install and remove the cartridge (just be sure to remove the cap first and make sure it’s properly screwed in when you install it).
Most models have some kind of an ‘On/Off’ switch, as well as a ‘Start’ button which connects to the electronic ignition. Just turn it ‘On’, wait a few seconds (if you listen carefully, you’ll hear a faint hissing sound as the butane is released), and press the ‘Start’ button. The butane will ignite (there’ll be a slight “whoomp” sound) and heat up the mat.
It’s easy to check whether the device is working by looking at the lens on the end of the appliance – if it glows, then the appliance is working.
On newer models like the MR450 and the Halo Patio Shield, there’s an indicator button or ring that lights up when the device is active. You’ll need to install one or more batteries to power the indicator light but, if you’d rather not, the device will still work perfectly – just look in the lens to see if the flame is lit.
Note: In some situations, the flame may go out – windy conditions, running out of butane and not properly screwing in the cartridge will all cause the device to stop working. I can always tell when it happens because I suddenly start getting bitten by mosquitoes! First, check the butane level. If that’s fine then take out the cartridge, rub the nozzle gently on a piece of fabric (I usually just rub it on my shirt), and reinsert it. That always does the trick (I suspect that the nozzle somehow “clogs” from time to time).
Mosquito Repellent Mat
The repellent mat slides under a grill on the face (or top) of the appliance. As the active ingredient is used up, the mat slowly turns from blue to white. Dispose of the mat when it’s all white. Each mat lasts about 4 hours.
Note that the grill gets quite warm when the appliance is on, so be careful handling the device and don’t pack it away until it has cooled down completely. That’s especially true for the Halo Patio Shield which has a plastic snap-on cover that fits on top to protect the inner workings from rain and moisture when not in use.
The repellent does smell (especially when a repellent mat is heated for the first time), but it’s not a strong smell and most people don’t notice it. However, as with any chemical, it’s never a good idea to inhale it and the packaging carries a warning to avoid breathing in the vapor. With normal use, this isn’t a problem.
About the Repellent
The Thermacell appliance uses allethrin, a synthetic version of a naturally occurring insecticide that’s found in chrysanthemum flowers (similar to pyrethrin).
Like most insecticides, allethrin is toxic to fish and other aquatic invertebrates. Use common sense and don’t toss used mats into ponds, lakes, rivers, etc. Most of the insecticide will have dissipated after use, but it’s still best to be cautious. And wash your hands after touching the repellent mat.
Does the Thermacell Really Work?
We tested the Thermacell Mosquito Repellent in several locations that have large mosquito populations. Without the appliance, we were quickly bitten by swarms of mosquitoes. After the appliance had been on for 10-15 minutes, there were no mosquitoes in sight and we were able to comfortably sit outside without getting bitten. In fact, lighting the Thermacell is the only way we’re able to sit on our back patio or eat outside in Tucson during the 9 months of the year that mosquitoes are active (including during the day). So yes, it most definitely does work.
A single appliance will emit enough repellent to cover an area that’s roughly 15’ by 15’. However, if it’s breezy outside, the area of protection will be smaller and I recommend placing the appliance slightly upwind from where you’re located. In strong winds, the repellent is quickly blown away so don’t expect it to provide protection (then again, mosquitoes usually aren’t a problem in windy conditions).
Who Is It Best For?
Initially, the company marketed the device primarily for hunters, campers, and outdoor enthusiasts. But they’ve since targeted the general consumer market because the Thermacell device is also perfect for use on decks, patios, or other areas where you’ll be sitting. Just place it on the ground, hang it from railings, or set it on a table and you can enjoy your evening without being bitten by mosquitoes.
Using the Thermacell Mosquito Repellent Device in the Garden
You’re not always sitting in one place, so how do you get protection while you’re moving about, such as when you’re working in the garden? One of the accessories that’s available as an additional purchase is a special holster to carry the appliance. It has pockets in which to carry extra repellent mats or cartridges and a clip on the back to attach it to a belt or tool bag.
The appliance is a little bulky so I clip it to the back of my pants while gardening at dusk. As long as I stay within roughly a 225 square foot area, the device provides enough protection to keep mosquitoes away. But when I move quickly from one side of the garden to the other, it takes a while for the repellent vapors to “catch up” with me.
If you register your product with Thermacell, you’ll double the warranty to two years. All products are guaranteed against defects in materials or workmanship under normal use. If there’s a problem, the company will repair or replace the item free of charge.
The range of Thermacell mosquito repellent devices is one of my all-time favorite outdoor products. The various models all basically work the same way – some with more bells and whistles, some with fewer – and they all just WORK. Light up one of these babies and within 10 minutes or so, the mosquitoes are gone from the area around it.
The one exception I’ve found is the Halo device with 4 butane cartridges. For some reason, even when it’s turned off, all four cartridges continuously leak butane. If I use it one evening (with all new cartridges) and turn it off when I’m done, by the next evening all of the cartridges are empty. I’ve never had a similar problem with any of the other models (and I’ve tried nearly all of them!). Because of that, I don’t recommend the Halo.
Where to Buy It
The Thermacell Mosquito Repellent Appliance is available at major retailers and specialty stores nationwide (look in the hunting and camping sections) but your best bet is to buy it on Amazon.
The original model is available on Amazon in a wide range of colors, along with repellent mat and butane cartridge refills and a variety of accessories, including the holster. The various product lines (including ones for outdoors, hunting, and home and garden) come in different colors and designs, but they all work the same way – go with whichever look or style you like best.
The models featured in the video above are shown below, along with the refill pack that we recommend (it’s the best bang for your buck).
No products found.
Now over to you – Have you found an effective mosquito repellent? Share your thoughts in the comments below!
Last update on 2020-03-28 / Affiliate links / Images from Amazon Product Advertising API
Enjoyed This Review?
If you liked this review, please sign up for our email updates with reviews, how-to articles and gardening videos!
The ThermaCELL Mosquito Repellent Appliance is effective at repelling mosquitoes within a 225 square foot area when there’s little air movement; great for use when sitting outside on a deck or patio. It’s less effective in breezy conditions or when you’re moving around outside of a 15’ by 15’ area.
Find it on Amazon