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ThermoWorks Thermapen ONE Review

Thermoworks Thermapen ONE is the newest addition to an excellent line-up of their instant-read thermometers. Its unmatched speed, accuracy, and feature set have raised the bar for cooking accessories. Over the past 6 months I have used this instant read thermometer on many outdoor and indoor cooks. Over this time …

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By Michael Haas


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Thermapen One Review
Confirming the Temp on My Halifax Beef Donair

Thermoworks Thermapen ONE is the newest addition to an excellent line-up of their instant-read thermometers. Its unmatched speed, accuracy, and feature set have raised the bar for cooking accessories. Over the past 6 months I have used this instant read thermometer on many outdoor and indoor cooks. Over this time I have developed a strong understanding of the Thermapen and I can provide an honest review.

Overcooked or undercooked food can leave a bad taste in your mouth, not only from the food but of the overall experience. Whether you are a professional chef or a weekend grill master, the most important tool in your chest is an accurate and reliable, instant-read thermometer. A meat thermometer not only is handy in checking the internal temperature of your meat, but it does so at incredible speed.

The Thermapen ONE is a clear improvement from its predecessors (Thermapen Mark IV/Classic) and puts up a tough fight with its competitors as well. For instance, while Maverick’s PT-75 and TP19X by ThermoPro come with a standard 12-month warranty, Thermapen ONE offers a 5-year warranty. It’s specs and features like this that made us award the Thermapen ONE as the best instant read thermometer.

byb2-table__imageRating 8.0Rating 8.0Classic Thermapen
  • Readings in 3sec or Less
  • Extremely Accurate
  • Splash Proof
byb2-table__imageRating 9.5Rating 9.5Thermapen ONE
  • Readings in 1sec or Less
  • Extremely Accurate
  • 360 Display

The ThermoWorks Company

ThermoWorks is a Utah USA-based company that focuses on optimizing temperature readings across many industries. Thermoworks products are featured across a wide range of applications from; food processing plants, HVAC, manufacturing, and pharmaceuticals.

Thermoworks are pioneers in manufacturing low-cost, high-speed thermometers based on a solid, working knowledge of thermodynamics. Their products combine impressive precision with efficient, pocket-friendly designs making them a favorite amongst both professional and home chefs. Manufacturing is done throughout the world including Europe, USA and Asia.

Thermapen ONE Overiew

We will now take a look at the specifications, performance, features, fit and finish and overall ownership experience of the Thermapen ONE.

Thermoworks Thermapen ONE Specifications

Operating Temp Range -4-122-degree Fahrenheit(-20-50 degrees Celsius)
Dimensions6.1W x 1.7H x 0.74D (inches)
Battery1.5 Volt AAA giving 2,000-hour battery life (without backlight)
Display SettingsIncrements of 0.1-1 degree: 360 auto-rotating display. Fahrenheit or Celsius.
Measurement SpeedLess than 1 second
Temp Reading Range-58-572 Fahrenheit (-49.9-299.9 Celsius)
Temp Reading Accuracy0.5 Fahrenheit (0.3 Celsius)
BacklightBuilt-in automatic backlight
ColorsRed, Grey, Pink, Blue, Green, White, Orange, Purple, Yellow and Black
Water Resistance RatingIP67 (Protected against temporary immersion 15cm-1m for 30sec)
IncludedThermometer, calibration certificate, instructions
Thermapen ONE Specs
ThermoWorks Thermapen ONE Unboxing
Unboxing of Thermapen ONE

Thermapen ONE Performance

ThermoWorks claims the Thermapen ONE will take an accurate reading in less than one second and we can verify this is true. Configured to a 0.3 degree Fahrenheit of accuracy, this thermometer reads to a time constant of 0.2 seconds. The readings are also impressively responsive to rising temperatures and help you check the temperature of your food in real-time. This optimal performance in temperature accuracy is backed by a NIST-Traceable Calibration Certificate that comes included with the device.

Food temperature recorded on a Thermapen ONE is displayed on an LCD screen that orientates itself quickly, irrespective of which angle you hold it in for easier reading. Customization of settings allows you to lock the display orientation and change temperature units but you’ll need to open back cover to adjust those settings. Don’t worry, we will show you how to do that.

A smart back-lit display helps read the temperature in low light, and the display switches off automatically if left untouched for over 30 seconds.

Backlit Display on Thermapen One
Backlit Display

The Thermapen ONE has easily replaced its predecessor, the much-loved Thermoworks Thermapen Mk4. And for good reason. Speed of temperature readings is important when your hand is above a 600-degree Fahrenheit grill.

Thermapen NIST-Traceable Calibration Certified – What Does This Mean?

ThermoWorks takes temperature reading accuracy very seriously and designs their devices to meet the National Institute of Standards and Technology (NIST) standards. This means that you are receiving a device that was professionally calibrated to the NIST standards in a lab environment. It is also documented and each Thermapen comes with this certificate of calibration. This means you have one of the most accurate temperature reading devices on the market.

ThermoWorks Thermapen NIST Certification
My Thermapen ONE certificate
ThermoWorks Thermapen NIST Certification 2

Overall Fit and Finish

Like its previous models, the Thermapen ONE is of a rugged yet elegant design. This thermometer comes with a textured rubber/plastic anti-slip material and is waterproof. The sturdy probe arm folds back into the sides of the thermometer when not in use. The textured grip makes it easy to use with both bare and mittened hands. What’s more, it’s easy to clean as well. The overall design speaks of great things coming in small packages- packages that can, in fact, fit quite snugly into your pocket.

The Thermapen ONE is a brilliant combination of thermodynamics and material science resulting in readings at the speed of thought.

byb2-table__imageRating 8.0Rating 8.0Classic Thermapen
  • Readings in 3sec or Less
  • Extremely Accurate
  • Splash Proof
byb2-table__imageRating 9.5Rating 9.5Thermapen ONE
  • Readings in 1sec or Less
  • Extremely Accurate
  • 360 Display

Thermapen ONE Features

Some features grab your attention of the Thermoworks Thermapen almost immediately. The backlight display is a lot brighter when compared to its previous models. While some may not consider this a game-changer, it certainly is handy while grilling in poor light or if you’re working in summer’s twilight.

The auto-rotation display makes sure that your temperature is facing the right way up, no matter how you position it. However, we noticed that the numbers are slightly larger to read when positioned horizontally. A motion-sensing sleep mode ensures that the battery is optimally used and lasts longer in battery cycles. While the default sleep setting is for 30 seconds, it can be customized for a longer period of time.

The waterproof feature of the Thermapen ONE is another thing to love. The device is rated at IP67, which means it can survive being submerged in water for short periods. This is not advisable though, and the unit is not dishwasher friendly. This thermometer can handle minor water spills or if you forget your device in the rain.

The battery performance in the Thermapen ONE is also worth a mention. Powered by a single AAA battery, this thermometer is known to last up to 2,000 hours if the backlight isn’t used. This marks a 500-hour increase when compared to its previous models. The battery compartment is easily accessible and is also the place to customize user settings: such as temperature scale, sleep/wake, display orientation, and so forth. 

Thermapen ONE Ownership Experience

No matter how hard you research before buying a piece of equipment, owning it is always another experience. Fortunately, we’ve known the Thermapen ONE to be faithful to its reviews and we’ll add our thoughts about this excellent product.  

How to Use the Thermapen ONE

ThermoWorks includes two instruction manuals: a quick startup manual and a separate long-written manual. Overall the Thermapen ONE is very easy to use. Here is a quick guide on using a Thermapen safely without damaging it.

  1. Simply extract the temp probe from the soft rubber clip holding it in place. It rotates in a counterclockwise direction.
  2. The display will automatically turn on when you pull the probe from its resting place. The display will orientate to the best position for viewing. This is helpful when switching hands on the Thermapen.
  3. ThermoWorks states that as a minimum you only need to insert the probe 1/8″ into the food to get an accurate temperature reading. This is great but typically when checking meat temperatures, we need to measure the coldest part of the meat which would be the center. Try your best to estimate where the middle is and probe that area.
  4. After 1 second you should see an accurate reading on the display. Take note.
  5. Remove the probe from the meat. I always wipe the probe with a dry rag or paper towel when I’m done probing.

What Not To Do With Your Thermapen ONE

Here are a couple of things to know to reduce the risk of damage to your Thermapen.

  1. When cleaning the Thermapen, I would recommend that you never submerge it in water. It is rated to handle this, but you are asking for problems as this is an electronic device. Just use a moist dish rag and wipe the probe and body clean. Dry and store in a safe dry area.
  2. When probing and checking meat temperatures, you might be inclined to try and flip the pieces of meat over with the Thermapen probe. Try to refrain from doing this. The Thermapen is not designed to withstand forces of that nature. It is only designed to probe in and out of the meat. You could damage your probe if you use it as a spatula or grill tong.

How To Change the Thermapen Temperature Reading from Fahrenheit to Celsius

Did the Thermapen arrive with the incorrect temperature display format? Here is the easy way to change the display setting on your Thermapen ONE.

  • Use a small Phillips screwdriver and remove the single screw on the back of the Thermapen.
  • Press the small ‘M’ button (menu button) once and the display screen with show ‘C or F’.
  • Press the small ‘S’ button (set button) once and the display will change the reading from either Fahrenheit or Celsius.
  • Press the small ‘M’ button again until the display reads ‘End’, after a couple of seconds the display will go back to temperature reading mode.
  • Re-install the small back cover and tighten the small Phillips screw.
Thermapen ONE Back Cover Removal
Phillips screw holding back cover
Thermapen Back Cover Off
Back Cover Removed
Thermapen Celsius to Fahrenheit
C or F Setting

Fahrenheit to Celsius Thermapen
Top right corner shows selected temp display
Thermapen End Screen
Menu Screen to End
Thermapen ONE Back Cover Removal
Re-install back cover

Thermapen ONE Accuracy Tests

I decided to see if the Thermapen ONE truly would deliver accurate temperature readings by conducting a boiling water test and an ice-cold water test. You’ll see firsthand how accurate the Thermapen ONE is.

Thermapen ONE Boiling Water Test

I live in White City, SK Canada, and our city’s elevation is 2004′. For every 500 feet above sea level, the boiling point decreases by 1 degree Fahrenheit. The sea level boiling point is 212F, so my city’s boiling point should be 208F. The picture below confirms the boiling point temp accuracy. It also obtained this temp in less than 1 second, proving the quick read time.

Thermapen ONE Boiling Water Test

Thermapen ONE Ice Water Test

I filled a glass full of ice and added water and waited a couple minutes. The water temperature measured was 32.1 Fahrenheit. It also obtained this temp in less than 1 second.

Thermapen ONE Ice Water Test

Customer Care and Warranty

Any repairs and servicing of your Thermapen ONE are handled by an efficient customer service team that guarantees you a rapid turnaround (within 5 business days). What’s more, the thermometer comes with 2 manuals; one that gives you ‘quick-start’ instructions and another, that gives you more detailed information.

Thermoworks’ Thermapen ONE comes with a generous warranty of 5 years against damages. While it’s twice as much as its predecessor, it is noticeably 80% longer than its competitors. An improved warranty from the standard 12-month period is very reassuring to buyers.

Would We Recommend The Thermoworks Thermapen ONE?

Yes. Absolutely Yes. If anyone has grilled over top of a 600+ degree grill while checking the temperature of a dozen or more chicken thighs, knows how fast you can burn your hand. Many other instant read thermometers on the market take 3-5 seconds for an accurate reading. Having a Thermapen that has a response time of around one second saves my arm hair and that is important to me.

Also knowing that I’m getting a very accurate measurement is reassuring and I never have to second guess what temperature the meat is.

This must-have tool brightens up almost every aspect of your cooking experience.

What we Like

  • The intuitive, 1-second accurate reading
  • The probe’s sensitivity to changing temperatures
  • It’s very easy to operate and can be used by both home and professional grillers
  • The bright temperature display makes reading easy in dull light
  • The water-resistant, rugged exterior in a compact, lightweight design
  • The grip of the device is suited for both covered and bare hands
  • The motion sensor that switches on/off the device automatically

What Makes Us Angry

  • Ummmmm
  • That I didn’t buy one sooner

While many might feel that the Thermapen ONE is overpriced, it certainly feels fair considering what you’re getting. With quality and efficiency that matches its claims, there is hardly anything to improve in terms of functionality with this product. At this point, we feel that the Thermoworks Thermapen ONE delivers what it promises and more.

Our Final Verdict

The Thermapen ONE is an excellent product from one of the best temperature measurement companies today. Guaranteed to bring home accurate performance and good-quality cooking, this thermometer gets the best results consistently.

It’s a stellar buy and does complete justice to its prestigious brand. From instant readings and user-friendly mechanics to cool customization options, this thermometer is a delight to work with. If you’re looking for a kitchen thermometer and want to know what quality feels like, the Thermapen ONE will not disappoint you.  

Looking for something a little more economical? Check out the ThermoPop 2!

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