Mr. Coffee MWBLK Plastic Mug Warmer for Office/Home Use

There is a problem cited throughout these reviews that since the mug warmer is not a hot plate, and doesn't reach higher temperatures, it can only help keep a mug warm. It cannot make hot a cup of coffee or tea from a cold start. I wondered about this, and tried it out, and yes, it is a problem. But there is a simple solution, cost about 10 cents, using a solution from physics and proven on long hikes. I tried it, and it works better than expected here as well. I can take a cup of water from a cold start to being just the right temperature for sipping, not quite steaming, but hot! Here's the physics: there are several types of heat, the most important in this case being radiant heat. Radiant heat is called radiant heat because it travels in rays. In this case, it comes up from the surface of the warmer, and yes, there is some other types of warming going on, but most of what seems to be happening to the liquid is that the radiant heat is traveling through it, and then dissipating into space. The cup loses other forms of heat too, but by just solving the radiant heat loss problem, you will have solved the entire problem of your warmer not being able to warm full cups of coffee or tea, or make cool water warm to start with for dissolving the tea or coffee in it. (I even use loose tea with this solution, and it works fine; it gets hot enough that it does not have to be a mix.) So what do you do to overcome radiant heat loss? A burner would just apply more heat. But if you wanted a hot stove in your office you'd buy a burner, for about 5x the cost of this, and then run the risk of injury in tight quarters. In this case, apply a radiant barrier. A radiant barrier can be fancy or expensive, but you can fashion a very serviceable and even decent looking one with practice out of about a foot of aluminum foil. Anyone who has been camping or tried to travel light while distance hiking knows that you can make a light pot cozy of aluminum foil that serves as a shield against win. The surprising thing is that this simple material we are used to using for wrapping pot roast has the amazing property as applied of cutting your need for fuel dramatically on the way to boiling water. So applied to the mug warmer, fill your mug, put it on, then by folding the aluminum foil a few times to a) stiffen it up, and b) fit around the cup, make a loose fitting wrap that sits just outside the mug, not too tight since you want to re-use it many times. Then apply a paperclip, preferably a small binder clip to joining the foil. Of course you can use other things as well. This way it lifts right off, and can be put right down. Of course, just going around the outside of the mug, the most important area is left open. So fold and refold a second piece of aluminum foil into a stiff square that rests on top of the lip of your mug. Actually this part alone is often sufficient to keep your coffee far hotter than the burner alone, and will work to heat up cool coffee. The additional loose wrap around part just makes it that more efficient. This really worked well for me, to the point I am very pleased, and don't have to run down to the microwave to re-heat my coffee or tea, but can do it from scratch, right on the cup warmer. I like the truly functional aspect of it, that I made it myself for ten cents, and can show a little creativity in sculpting it into something that looks alright, plus it recalls some good hikes . . . But if this is too man cave for you, there are pot cozies you can buy on amazon. Just make sure that they have a radiant barrier in them, or put some foil inside them too, tho no one will see it. That way, you keep recapturing radiant heat, and this is probably 90% of the battle. This way, by turning the radiant heat back on the cup, and back again, again and again, you multiply its effect pretty dramatically. IF this proves helpful, or you think it may, please give it the thumbs up. I'd like to see it rise as a helpful review so it can help solve what so many people have complained of.

I had a very nice Christmas (thanks for asking!), and I got lots of nice gifts. But the best gift of all that I received was the smallest item of them all. Mr Coffee Mug Warmer, take a bow... Truly, this mug warmer* really has changed the quality of my life significantly over the last few weeks. Now, you might read that statement and think, 'wow, your life must really suck for it to be possible for a mug warmer to make it better'. But no, my life doesn't suck. I just really, really like hot tea. You see, I work at home. And I don't have any work colleagues to shoot the s*** with - so, to keep me on my toes, I use caffeine. Lots and lots of caffeine. But, much as I like caffeine (delivered through the medium of tea and, of course, it's more sultry sister, coffee), I get very sad when it goes cold. Indeed, taking a swig of cold tea or coffee is about as pleasant an experience as, say, getting smacked in the face with a wet pair of underpants (we've all been there, right?) Anyway, so I got this mug warmer and I switched it on and, lo and behold, there are no more such unpleasant moments in my life anymore (until someone turns up with a pair of wet underpants anyway). One of the small but incredibly irritating daily occurrences that I had come to think was inescapable has now been resolved! (Yes, things can actually get better!) So now, when I am distracted by a Skype call or any other task and so have to abandon my tea for 20 or 30 minutes, I can now confidently return to it knowing that it will still be piping hot (or very warm at least) and utterly satisfying. In other words, this mug warmer product delivers the goods and then some. The tyranny of cold tea has been defeated. And the misery of having to trudge downstairs to heat it back up in the microwave is no more. (Heck, at this rate I might never need to move from my office chair again - progress, eh?) But seriously, if you want a cheap mug warmer that keeps your drink at approximately the same temperature as you prepared it at, then this warmer will do the job nicely. I leave it on all day (yes, us home workers are total rebels, didn't you know?) and it has paid for itself many, many times over by now. *One thing that I have to say is that, while brilliant, this product is NOT a 'warmer' - i.e. it does not *warm* your drink up at all. Rather, it *maintains* your drink at approximately the same temperature as you prepared it at and for a good length of time. For example, if I prepare a cup of tea (which I am about to go an do, by the way), and put it on the warmer, it'll keep it at the same temperature - with only a very slight loss of heat - for up to an hour and beyond. As a voracious tea drinker, I've never actually let a mug linger long enough to see if there is indeed a point at which it will lose all heat. So surely that's a good sign, no? Bottom line: how can you call yourself a serious fan of hot drinks and not own this product? Shame on you! SHAME! Update (2 weeks later): bonus feature detected! If you are like me in that you tend to spill drinks and in the process your mug tends to drip with coffee a lot, you are going to love this... This mini hot plate warmer will sizzle all drippage away instantly once you place your mug down on it, meaning that you can also avoid any future coffee stains on your table. Then all you need do is wipe the warmer clean once it is turned off / cooled down (unless of course you're like me and you don't care). Score!

OVERVIEW: This does what it is supposed to do. It is not fancy; it is a basic warmer. But it does the trick. For this price point, it is excellent! My office is usually cool, so my coffee and/or tea would never stay warm. This warmer does the trick. I haven't had a cup of room temp coffee or tea since! Love it. CUP TYPE: I do use this with a basic 14 oz. ceramic cup with the "lip" around the bottom. Many have stated that you need a flat-bottomed cup or a metal (like a Yeti) cup, but you don't. I tried a Yeti-type cup once and the entire cup was so hot that I couldn't touch it. Not recommended! START WITH HOT: Please note that this product is designed to keep your beverage warm, not to actually warm it up. You can't start with a cold or room temp beverage and expect it to heat it up. That is not what this one is for. But, if you start with a hot beverage, it will remain hot on this warmer. TEMPERATURE: This product has no heat settings. It is either on or off. But again, for this price point, that's what you get. The plastic housing is slightly warm to the touch, but nothing to worry about. But don't touch the heating plate. It is very hot! APPEARANCE: The heating surface, as many others have mentioned, gets scratched easily by the ceramic cup bottom. As you can see in the photo, mine got scratched also. However, since I have a black cup sitting on it all the time, you really can't see that it is scratched. It doesn't bother me at all. SUMMARY: I do recommend this product if you are looking for something to keep your hot beverage hot. I would recommend unplugging it when you are not around. Others have noted them shorting out when unattended, even if turned off. Mine is plugged into a power strip/surge protector that gets turned off every day when I leave the office, so all of my electronics are completely off when I'm not there. UPDATE: I purchased this in January 2022. It is now September 2025, and it is still going strong! And the scratches in the photo from my original review look exactly like it looks today (but maybe a little dirtier. LOL) I came here today to purchase another one for a different location, but I'm uncertain that it's worth $21. I only paid $11 for it 3.5 years ago. I realize that inflation has been bad recently, but almost double?! I may need to look elsewhere.

OK, I read a number of the reviews posted here before purchasing this mug warmer, and did a little research to check what the power used (wattage) was supposed to be. The manufacturers seem to want to keep this a mystery for some reason -- all of them. There were reports that this Mr Coffee device had the same wattage rating as other similar mug warmers that had decent feedback ratings. So, I decided to try it. The power number mentioned was 17 watts, which sounds about right for a device this size. The watts of power generated is THE most important characteristics of any heat producing device and this Mr Coffee mug warmer seems to live up to the purported 17 Watt rating. They don't put any power or energy information anywhere on the packaging material and there is no information in the small instructions pamphlet either but the bottom off the device says: "120 V 60 Hz 17 W", so, 17 watts it is. Now, if this electrical device consumes around 17 watts, you can assume some of the heat energy is lost to the table and the edges of the plastic housing and if you put your hands around the device, there is some loss there and my desk beneath does get a little warm. So, clearly 17 watts is not going into the cup. But for such a simply made device, like all the others I see advertised too, it appears to generate a majority of the heat energy at the indented area where the cup will sit. And by the way, the heating are where a mug sits is 3-1/4 inches in diameters -- which will accommodate some pretty big mugs. The depressed area where your coffee mug sits gets noticeably warmer than the sides of the device. It is hot but not so hot I can't touch it. I wouldn't want to hold my fingers there for very long but it's not like its glowing red. It's touchable. So, I took it out of the packaging, plugged it in, set a cup of coffee on it, and did a little work -- like maybe twenty minutes. The coffee was a bit cold to start, not even cool, and when I picked the mug up a little later the coffee was warm, the mug was warm.. The mug warmer doesn't heat it to a hot coffee temperature but check it's name -- it isn't supposed to. It "warms" the coffee. As a couple of reviews pointed out, the manufacturers are skirting the boundary of generating enough heat to make it dangerous to be left heating on a desk. You can't have a relatively small, inexpensive plastic device have a red-hot burner on it, not when it's intended use is sitting next to my monitor amidst piles of note and maybe near a textbook or two. If you want really hot coffee, clear a space on your desk and get a true hot plate with which you can also fry bacon. Or get a small stand to hold a microwave. After all that, I was quite pleased with how effective it was in "warming" a drink. If you want it to make your coffee hot hot, you will be disappointed. If you want your coffee to stay warm, it does it's duty.

** PLEASE read my review until the end! ** I want to start by saying this is my FAVORITE mug warmer that I’ve bought, and I’ve bought many over the years. It’s simple and to the point - just plug it in and use the on/off switch, no charging cords to keep up with, no APP you have to download because it’s controlled from your phone, no special mug you have to use, not even an instruction manual cause you don’t need one. It weighs next to nothing so it’s super easy to just throw in your bag when you’re traveling. I’ve taken it in my carry on thru airport security without any problems. So, if you’re a “slow sipper” like me, who likes to enjoy your morning mug over a longer period of time, this warmer is perfect. And it allows you to go thru your mug collection (coffee lovers all have a mug collection), instead of being forced to use expensive insulated mugs that you have to remember to wash everyday (I never remember). So, this warmer is both super easy to use, truly portable, and keeps my coffee at just the right temperature without a bunch of different controls and settings to go through, or worrying if it has enough charge to use because I can’t find the charging cables. (Seriously! Rechargeable does not always equal convenience! We all have enough charging cords to keep up with already!) I love this warmer so much that I’m getting ready to purchase my 4th one…..I’m also only giving it 3 stars because I’m getting ready to purchase my 4th one. As well as they work, they usually don’t work for very long…..maybe 5 to 6 months at a time. They’re very lightweight because they’re very cheaply made. You will eventually crack the plastic casing simply by putting your mug down the wrong way. And tho this warmer starts out extremely nice in appearance, low key and clean lines….it doesn’t stay that way. Very quickly you’ll notice that the black finish across the hot plate of the warmer will begin to wear off and after a time, it starts looking like a piece of garbage sitting on the table beside your favorite chair. After that, it completely stops working all together. Another reason it only gets 3 stars is because it has doubled in price since I purchased my first one, which I only paid about $10 for. I know inflation is alive and well in this country, but doubling the price for something that is of no better quality than it started out as is ridiculous. But, they’ve got me……hook, line & sinker. Why? Because they really do have the best design…..it just shouldn’t be disposable. My cheapo coffee maker is well into its 11th year of life. My mug warmer SHOULD have the same kind of life span. Now, I fully expect them to hide this review way down towards the bottom where no one will ever see it. If you’ve paid attention, only the “good” reviews end up on the first page underneath the product. So, I’ve tried to hide my negative comments within my positive ones. Let’s see how honest Amazon is with the placement of their reviews. They want honest product reviews so their customers can make well informed choices when deciding how and where to spend their hard earned money…..well, this one is honest - from a customer who has repeatedly purchased THIS product FROM Amazon. The attached photos are from a warmer purchased 1/26, showing the daily use of one mug of coffee. As of today, 6/11/26, it has stopped working completely.

Mr. Coffee mug warmer: As I use it, I will update this review. Cord is long (3.5 feet), the actual heating surface is 3 and 3/8 inches diameter, and it's well made and inexpensive. It turns on with a red light on the unit (unlike another brand that has the on/off switch on the AC electric cable). A superb substitute for schlepping my soups in with a thermos every day (hard to clean, extra work at home, etc.) My goal: warm soup at my desk. I don't want an open flame (e.g. alcohol cook stove), or a very hot 750+ watt cooking element/hot plate. A small Crock pot is hard to eat from and wash--so, I thought this Mr. coffee might be what I want. I don't drink coffee, but could see using it for hot cocoa. The test: I can put a room-temperature full 8 ounce Campbell's Soup--chicken noodle, to be exact--contents in an enamel-coated aluminum 12 ounce cup with lid, and in 30 minutes it's fairly heated and I could eat it, but in one hour, it's nice and toasty and ready to eat. It's hot enough that I cannot touch the bottom of the cup. I was concerned about the honest reviews that said this does not get hot enuogh--but after using daily for a week, it's mighty hot. I certainly cannot touch the warmer surface--it's far too hot. My office is not near a microwave, and this is a lifesaver for me. I may try canned stews next. I adore eating at my desk. A fellow office mate actually warms water--not to boiling, but very hot--over and hour and then dumps it from the cups into camping meal bags (cook in bag types, like Mountain house) and eats well every day. Sure, if someone had a microwave it's faster, but why challenge the entire office for microwave time in the grody kitchen room when you can set this out an 11AM and be eating well by noon. Here's the exact cup I use, which fits the Mr Coffee well. Coleman 12 Ounce Enamelware Coffee Mug (Blue) Tips: The cup makes a big difference. I use an enamel Coleman aluminum cup, which holds one soup can well (not too close to the top), and conducts heat exquisitely. I have no clue is a hard and thick ceramic coffee mug would work. Also, I put a lid on the cup to hold heat, and so I don't get paperclips and junk in there while it "cooks". Lids reduce heating time by 18% (according to camping websites). I use a simple ceramic drink coaster that I had at home for my lid--any nonflammable lid would work. The lid helps. Also, the Coleman mug that I use is flat bottomed, thus using the entire heating element successfully. A curved bottom mug may not heat as well. P.S> Okay, I just did Campbell's Vegetable Beef soup in it today, thick and I added no water, and it took about 1.5 hours to get fully hot. Still worked great, but clearly the thicker the soup, the longer the heating time. Also, the heating is most intense at the bottom of the mug or cup, so (1) stirring helps, and (2) a tall style ceramic mug or cup would not be as good as a squat one. I bought a second one for home since I liked the first one so very much, and to test if the first one was a fluke and just extra hot or something. Guess what, no fluke. The first and second are equally as hot. Postcript: just for kicks, I put tap water at room temperature in the blue Coleman cup for 60 minutes on the Mr Coffee warmer, and I couldn't even stick my finger in it at all. It was hot! Not boiling, for sure, but clearly hot. I wouldn't want it that hot to drink or to eat. And, so, I added an ice tea bag and took it off the Mr Coffee and drank tea. PLenty hot! Lovely! Bon appetite!

This product lasted only a mere three months. Grrrrr!!!! It worked nicely at first but has now conked out. I am very disappointed. Of course Amazon won't accept a return after a month (which is a silly policy and a real pain in the tukus), but I am going to seek out Mr. Coffee and ask for a refund based on the warranty. FIRST, what happened to create negative review: The warmer was working fine. However, I noticed the unit making a very weird electrical buzzing sound; a very unsettling sound that made me instantly squirrely. I checked it and the unit was plugged in but was not turned on. I thought maybe some internal wiring was a bit loose or it was dirty. I unplugged the unit and the buzzing instantly stopped. I cleaned it carefully and plugged the unit back in. The buzzing started right back up again. The sound is very familiar to most of us...that disconcerting buzzing sound that makes you feel like something is about to catch fire due to bad wiring. I double and triple checked to make sure the unit was not turned on, and this made me even more nervous. i tried leaving the unit unplugged for a few days then try again. Same result. Now it is just a piece of junk I don't think I can even recycle. SECOND, product review before failure: As other reviews have mentioned, this will keep maintain the temperature of liquids that are already hot. It won't heat up liquids that are lukewarm. For any coffee warmer, you have to make sure that your cup is sitting directly on the warming plat. If your cup has a small stem or stand, it won't maintain the temp. of the liquid. Thick walls or base of your cup will diminish the warming capability, but not really by that much, I actually found a very unique use for this as well. I like candles very much. When you light candles in jars or glass containers, there is always a small amount of wax that doesn't burn before the wick goes out. I want all the smell-good from the candle! So, I put the jar on the coffee warmer and it warmed the glass enough to melt to leftover candle wax. It was a nice way to enjoy the aroma of the candle and finish off the rest of that wax in the bottom of the jar. Another brand of warmer will do the same thing for me. The very few benefits of this product are certainly not worth the risk of the price and the freaky electrical failure I experienced. I am going to seek out another option and, based on my experience, I would suggest you think about doing the same. Take care and happy shopping!

This mug warmer has been a total lifesaver at work. I have a habit of getting coffee in the morning and sipping on it until lunch. I also have a habit of getting tea in the afternoon and sipping on it until closing. This is a problem because I like warm beverages. With this mug warmer I can take my sweet time drinking whatever I want and it’ll still be the perfect temperature. I have used this warmer 5 days a week for months. I had realistic expectations for this product and it’s done everything I could have asked for. Does this warm drinks? Absolutely. Does it keep them warm for hours without melting my desk? Also yes. Does it warm an extra large mug all the way through evenly? Obviously not. It heats from the bottom and it can only do so much. It does a great job of keeping a mug warm starting from the base and heating upward. If you have a large mug full of liquid, the top will be cooler than the bottom. To counteract that you can either stir it occasionally or place a silicone mug topper on it to retain the heat. I use both methods depending on what I’m drinking and how slow I’m being. If it’s currently busy at my desk, I place a silicone mug topper on my mugs to keep them warm and to ensure I don’t drop a staple into it accidentally. If I’m focusing on something and enjoying my drink, I using the stirring method which usually doesn’t consist of stirring so much as just me swirling the contents of the mug around a bit and that does the job. After months of use, my warmer has some rings and small signs of wear on the heating plate but considering the amount of use that I get out of this thing, it looks fabulous. Overall I would recommend this to anyone. The price is great, it looks classy without being obnoxious, it keeps drinks warm without them getting too hot, and it doesn’t harm the surface it’s sitting on. I would 100% buy this warmer again and I can’t recommend it enough.

Si buscas un calentador para taza, por mucho esta es la mejor opción, sobre todo si amas tomar café, té o cualquier bebida caliente en general. Tengo casi año y medio, y puedo confirmar que sigue funcionando a la perfección, mantiene caliente mi bebida usando cualquier taza (de cerámica obvio) con un tamaño promedio. Incluso ya se me ha caído 2 o 3 veces del escritorio (claramente no lo recomiendo jajaja) y ni así dejó de funcionar bien. El cable considero es lo suficientemente largo, mide más de metro y medio. El único detalle es que el recubrimiento en la base se pierde con relativa facilidad conforme a su uso pero no afecta en nada, por el precio es aceptable. EXCELENTE CALENTADOR :D

I got it replaced earlier but the new one is also not working. Please refund

This keeps my tea hot longer than not using it. If the cup is full it can't maintain the hotness but it certainly does delay it getting warm by quite a while. I used a cup that conducts heat well so it transfers more heat from the element to the cup. When the cup gets about half empty it keeps the remaining liquid quite hot. Now, I have read more than enough reviews to know that whats perfect for me, if freezing cold to others who have burned their mouth to no feeling at all. It keeps my drink perfect. I'm VERY happy with this. For the ignorant who think you can heat up a cup of coffee or tea with this or other absurd demands on a product obviously never able to do so with the current it draws, well, you can't! DUH! If it COULD do that, then it could burn the tea/coffee if left sitting for a long while. This, keeps it just right for me. Even after half an hour, its still almost as hot as when it came out of the kettle. Please note - it depends on the type of cup you use also which makes sense. Try using a ceramic tile off the space shuttle to make your cup and see how well this can heat it up. Well, a blowtorch couldn't heat it up with one of those. Be realistic in evaluating things. I shudder when I read some comments. Its like downvoting this coffee warmer for not remote controlling starting your car. This does totally fine. I'm very satisfied!

Waste

Was not clear the wattage