Why Your Ember Mug Says Empty And How To Fix

The Ember Mug is a smart battery powered mug that heats your tea or coffee and keeps it at the perfect temperature. But sometimes it malfunctions and the mug says it's empty even when it isn't.

What are some of the reasons your Ember Mug says empty and how can you fix this issue so it continues heating your drink to the right temperature?

The Ember Mug may think it's empty when you've just added cold milk to your tea of coffee due to the change in temperature. If your drink is under 100ºF (37.8ºC) the Ember Mug will not register it and may display as empty and occasionally honey that has collected at the bottom of your Ember Mug can mess with it's sensors and make it display as empty.

Most of the time fixing this is as simple as opening the app and manually adjusting the temperature you've set your mug to. This will activate the heating element and the mug will then realize there is liquid in there and it will operate normally.

Why Does Your Ember Mug Say Empty?

EMPTY: Displayed when the thermal sensors are not recognizing a change in temperature present in the inner vessel. This notification may also show if liquid is not present or the temperature rapidly decreases (caused by adding cold creamer).

1. You've Just Poured Cold Liquid Into Your Hot Drink (Drastic Temperature Change)

Let's say you've made a tea or coffee and poured it into your Ember Mug. Then you grab some cold milk out of the fridge and pour a splash (or a bit more of a splash) of cold milk into your coffee.

This will drastically change the temperature inside the mug extremely quickly. The temperature of your drink will also be uneven with some hot spots and some cold spots if you don't stir your milk.

I don't know exactly how the Ember Mug detects if the mug is empty or full but it seems drastic changes in temperature can trigger the Ember Mug to think it's empty.

To avoid this pour in your cold milk slowly whilst stirring your tea or coffee so the temperature change isn't as extreme and the entire cup of tea or coffee is a uniform temperature.

If your cup has said empty then give your drink a stir or swirl and then you can go into the Ember App and manually activate the mug by adjusting the temperature.

2. Your Drink Is Too Cold

I recently did an experiment where I tried to heat up a cold cup of coffee using the Ember Mug.

It took a whopping 40 minutes to heat up the coffee and as you can see on the video on many occasions the app actually showed the cup as being empty even though a few seconds earlier it stated the exact temperature of the drink?!!

On this page Ember states that the drink in your Ember Mug must be above 100ºF (37.8ºC) in order for the Ember to recognize that liquid is present. So if your drink is below this temperature then it may say that the mug is empty.

Maybe this has something to do with the way Ember uses temperature to sense whether or not the mug is empty.

Maybe anything below 100ºF is considered room temperature and this is how to mug knows when it's empty. Honestly I don't know the inner workings of the Ember Mug but if your drink is below this temperature it might display as empty.

The solution to this is either to go into the app and manually change the temperature setting to activate the heater. I also found constantly moving the mug around keeps it active until it gets over 100ºF.

You can also heat the liquid up externally in the microwave or on the stove and pour it back into your Ember Mug. Just make sure you don't actually put your Ember Mug in the microwave as this will break it!

3. Honey On The Bottom Of Your Mug

Apparently if you like to mix in honey to your tea or coffee it can collect on the bottom of the mug and this can interfere with the temperature sensor and cause the Ember Mug to think it's empty.

It doesn't mean you can't use honey it just means that you should try to stir it every now and then if you do to make sure the honey doesn't all collect on the bottom.

4. Your Mug Is Broken

If your Ember Mug keeps saying empty and you've got none of the problems up above then there is a chance your mug is broken.

It could be a faulty temperature sensor or something. If this is the case get in contact with Ember customer support and see if they can help you.

I've heard really great things about their customer support so they should be able to solve the problem for you and if the mug is faulty and within it's warranty period they might even send you out a new one.

5. Your Ember Mug Is Actually Empty

Look I know you didn't come to this article as it's blatantly obviously for this but it's got to be said. If your mug is empty then chances are it's going to say it's empty.

How To Fix an Ember Mug That Says Empty

If your Ember Mug is displaying empty when it's actually not empty there are a few simple tricks you can use to activate the mug and get it working again.

1. Use The Ember App To Manually Adjust Temperature

The most consistent way I have found to activate the Ember Mug when it thinks it's empty is to go into the Ember App and manually adjust the set temperature.

This will turn the heater on and then the mug should detect that there is liquid in there.

If it's under the 100ºF (37.8ºC) then it'll turn itself off within 15-30 seconds but if it's above that temperature it should stay on and work just fine.

2. Stir Your Drink So Temperature Is Even

Try stirring your drink so it evens out the temperature through the mug and this will stop the sensors from freaking out and thinking your mug is empty.

You can combine this will manually activating the mug through the app.

Stirring your drink will also remove any honey that has settled on the bottom and stop that problem as well.

3. Move Your Ember Mug About

Ember Mugs have a built in accelerometer that detects when the cup is picked up or moved about.

When the mug is picked up or moved it becomes activated and this can sometimes be enough to shift it from thinking it's empty to working normally.

4. Heat Your Drink Up Externally Before Putting Into Your Mug

If you suspect that your drink is a bit too cold for your Ember Mug to work then tip it into another microwave safe mug and warm it up. Or warm it up on the stove if you prefer to heat it that way.

Once warm pour it back into your Ember Mug and see if that fixes the problem.

5. Perform a Reset

I talked about this in my article on how to fix an Ember Mug that isn't heating but you can perform either a soft reset or a hard reset to try and fix the error.

To do a soft reset click and hold the power button for 3 seconds. This will turn the mug off and the light will fade to show its turned off.

To turn it back on press and hold the power button until the LED light illuminates.

To perform a hard reset on the Ember Mug:

  • Press and hold the power button on the base of the mug for above 15 seconds
  • LED will blink blue, the yellow, then red to indicate it's being reset
  • Once you see these 3 colors let go of the power button
  • Once the LED pulses back to white you know the reset is successful

To perform a hard reset on the Ember Travel Mug

  • Use a paper clip and place into the hole on the bottom until you hear a click
  • Hold for 10 seconds until the text panel displays the word reset

5. Get a New Mug – Contact Ember Support

If all of this fails then get in contact with Ember customer support and let them know about the problem and see if they can send you out a replacement mug.

I've heard the customer support team is really good so they should be able to help you.

If you've owned your mug more than 1 year and it no longer has any warranty then maybe it's time to buy yourself a new Ember Mug. You can see the latest prices and colors of the Ember Mugs by clicking the links below