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Automatic Coffee Cup Warmer Answered

I was given a coffee cup warmer many years ago. What made it so great was that it only turns on when there is a cup sitting on the plate; remove the cup and the warmer turns off. The other great feature about it, is that it has a higher temperature than any I have purchased since.

There is no name thereon so cannot check to see if they exist anymore - no luck with Google so far.
What I would like to do is either be able to safely adjust a current model so it is somewhat hotter or, preferably, also make it automatic. Making it hotter is the first priority.



I have a Rival model BW8M that is probably twenty years old. It works
great, but is kind of broken and doesn't sit level anymore. I need to
replace it, but of the five I have bought, none of them actually get hot
enough to keep my coffee more than lukewarm.

I have a stainless
mug with a lid. It works great on the old Rival, but not on any of the
new ones, they all are pretty weak. How can these manufacturers get away
with making products that don't work; but more importantly, how can I
modify one to make it actually get hot?

You have t understand the law.
If it is hot enough for a decent coffee or tea than it is hot enough that it can burn you.
That means a possible law suit so they lower the temp.
Same reason why it is so hard to get a hot coffee in a fast food outlet.
The heating is controlled with a simple bi-metal switch, they are available for a few bucks in almost any temp range.
80°C should be fine here.
Problem is that most of these units are not designed to be tampered with.
Might be hard to remove the old one unless it is placed outside the heating coil.

I solved my problem by buying a copper-plated stainless steel, vacuum insulated mug. I then drilled a small hole above the handle, and injected a few CCs of mineral oil into the area between the exterior and interior. I used a soldering rework gun set to 450 degrees and let it run inside the mug for a while to fully heat it up (thereby expelling the air between the layers), then soldered the hole up to close it.

The mug is still vacuum insulated, but the bottom inch or so has mineral oil in it. The mineral oil transmits heat from the mug warmer very efficiently, and a lid on the mug keeps the heat in.

My simple RIM-888 mug warmer (which apparently is a candle warmer) makes my coffee too hot to drink sometimes. Especially when it gets near empty.


leave a picture I might be able to find it


a ceramic mug on a hot plate may crack. but you should be able to boil h2o.


.  Can you tell if there is any control circuitry?
.  If it is simple on-off control, getting more heat out will probably require replacing the element. If the plate moves up and down, I'm guessing that the motion of the plate triggers a switch which powers up the element constantly at full voltage.
.  If the plate doesn't move, there may be a non-contact sensor of some sort and possibly a more sophisticated temperature control that can be tweaked.
,  Just guessing.

The plate does not move,  there is a non-contact arm that is activated by a small magnet glued to the bottom of the cup. In fact, I have attached a magnet to another cup and it, too, works fine. This warmer is great and creates the highest temperature of all warmers I have bought, I would love to buy more since this one is gradually falling apart (about 20 years old),  but with no I.D. I cannot tell who makes/made it.

Hence, I would like to increase the temperature somewhat on the newer models - and, yes, I use Jayefuu's suggestion of keeping the cups covered, and it certainly helps, but not enough since we like our coffee "sipping" hot.

.  Post pictures and maybe someone can help you ID it.
.  You should be able to modify most warmers by transferring the magnetic switch to the new unit.
.  How modifiable a new unit will be depends on how it's put together.

Put a coaster on top of your mug while it's on the warmer. It'll stop heat escaping so your warmer will heat it to a higher temperature.

Thanks, Jayefuu, for your suggestion. It so happens, we do just that and, yes it does help, but we prefer our coffee to be "sipping" hot, and the newer hot plates simply cannot achieve that.