Is your coffee maker not heating up properly? There might be some electronics in urgent need of repairs. Here’s 5 possible causes why this happens, and how you can fix it!

Can you imagine a morning without coffee?

If you’re anything like me,  there’s no way that you can start your day without a fresh, hot cup of Joe. Which is why I know setting your coffee maker to “brew” the delicious beverage only to find it’s still cold and half-prepared, can ruin the rest of the morning.

The good news is, that the causes behind this occurrence are not that hard to identify, and even simpler to fix.

Below, you’ll find a list of all of them, and who knows? Maybe even a bit of extra knowledge.

Ready? Let’s go!

Your Coffee Maker Might Be Having Trouble Heating up Due To…

  • A blown fuse
  • A faulty thermostat
  • A bad heating element
  • A broken switch
  • A calcified thermoblock

Believe it or not, factors such as the amount of minerals in your tap water can greatly contribute to the formation of unwanted sediment and other chemicals.

These can obstruct important parts of your machine and leave you with a cold cup every morning!

So, if your coffee maker’s temperature problem is caused by any of the factors listed above, worry not. Fixing them shouldn’t take long, and the replacement parts are fairly easy to come by.

#1 You Have a Blown Fuse

Fuses blow to protect your appliance

Coffe Maker Blown Fuse
A fuse is simple in concept: current flows through a thin metal wire, and when that current gets too high, the metal heats and melts, breaking the circuit.

Fuses allow for a controlled passing of electricity into your coffee maker. They are specifically designed to regulate the amount of electrical current that flows through them and break when there’s an overcharge, so your appliance is safe.

If your coffee maker is not heating up properly right after a blackout or any other power surges, the fuse inside it probably blew to protect the rest of its components.

Don’t worry too much, though, fuses are a dime a dozen!

Solution: Unplug your coffee maker, and get a screwdriver to undo the screws at the top, they’re usually beneath a plastic top. Once you’ve done that successfully, you should see the coffee maker’s guts and the blown fuse in question.

Remove it from the slot and replace it with a new one you bought at a hardware store.

#2 You Have a Faulty Thermostat

Have you ever wondered how your coffee maker knows when it’s time to shut off?

Well, it’s thanks to its thermostat. This component is responsible for detecting the temperature of the water you’re brewing your coffee in and regulate it accordingly.

When the thermostat fails, it might be getting wrong readings, and think the water’s already very hot, when in reality, it’s not.

Solution: You don’t have to throw out your thermostat right away. If you have a multimeter, you can test the component for conductivity.

If you choose to take this route, you’ll have to follow the indications from the previous point to expose the coffee maker’s guts. A positive reading on your multimeter, means the problem lies elsewhere!

#3 Your Heating Element Is Faulty

Cold coffee? Your heating element is probably broken

If you’ve read any of our previous articles on water-heating appliances, you probably already know that a heating element is what produces the actual heat within your device.

It takes the electrical energy from your wall outlet and transforms it into energy that heats the water in your coffee maker almost to a boiling point.

When this component fails, there’s just no way your coffee maker can heat the water. And that’s how you end up with a cold beverage.

Solution: To fix your heating element, you have to take apart your coffee maker, expose the component, and do another multimeter test.

Remember, if there’s conductivity, you keep it. If there’s not, you get a replacement. It’s as simple as that!

Coffe Maker Heating Element Replace
The heating element serves two very important functions in the coffee-making process. It heats up the water before it is sprayed over the coffee grounds and it keeps the coffee warm after it’s made.

#4 There’s a broken switch

A malfunctioning switch can be problematic

Broken switches are probably the most annoying cause of this list.

The coffee maker looks and works great, with the only exception that the water is cold! Diagnosing a bad heating element, a broken thermostat or a blown fuse is oftentimes simpler, as the symptoms are more obvious.

When a switch in your coffee maker fails, you might be tricked into thinking it’s accepting the commands you’re programming, but that’s not the case.

Now, before you throw out your coffee maker, take a breather, fixing this is very easy.

Solution: Same as before, take your coffee maker apart, bring out your multimeter,  and test for conductivity.

Replace it if necessary and get back to enjoying your coffee.

#5 Your thermoblock has sediment

  Sediment is the enemy

Having a calcified thermoblock is the worst!

But before going on about why I hate it so much, let me briefly tell you what your thermoblock is, in case you don’t know.

This component is a small block where water passes through a thin pipe. As it goes through, it heats the liquid to almost 100 °C.  When sediment forms in this thin pipe, the water going through it cannot make proper contact, thus compromising the heating efficacy of the process.

While this is much more common in older coffee makers, the minerals in the water you use could also play a part in accelerating the rate at which sediment forms.

Solution: To fix this problem, you’ll have to descale your thermoblock’s pipes.

This should get rid of the unwanted sediment that has formed in them and allow for proper water-pipes contact in the future.

If you want, you can also try doing the descale process with vinegar.


Coffee makers are an essential component to our everyday lives.

Almost two billion cups of coffee are consumed every single day! And while those numbers are probably not strictly belonging to coffee makers alone, it’s undeniable that they are very useful.

If your coffee maker is not heating up properly, there’s a wide range of problems that could be causing this inconvenience.

Having tools like a multimeter handy at all times can be the difference between keeping viable components, and spending unnecessary amounts of money on replacements you don’t really need.

That being said, sometimes the issues are more technical than expected, and the solution might be more complicated than you thought. If that’s the case, you can always contact an experienced coffee maker technician and have them take a gander.

This is especially advisable when your appliance is still under warranty coverage, as tampering with it might void it and leave you stranded.

No matter what route you choose, be sure to always put safety as the #1 priority in any project you undertake.  And always unplug your coffee maker before examining it.

I want to thank you for sticking with me all the way to the end of this article. If you found it useful, why not take a peek at our other great resources below?

Happy projects!