When your Moccamaster starts malfunctioning, it’s reason enough to question its durability -One minute it brews a fantastic cup of coffee, the next it suddenly stops working.
The most common reason your Moccamaster fails is because you need to descale it. Failing that, the footplate or spring might be out of place or it may be a fault with the heating element.
In this post, we’ll discuss the most common reasons why your brewer is not working and provide a troubleshooting guide.
Why Listen To Us? Well, because we KNOW coffee! In fact, we make our own coffee, coffee machine cleaners, and reusable capsules which we've sold to over 41 countries. Our team ouf experts include Tristan (an engineer), Claire (a food writer) and Richy (a barista). So, whether you're looking for a recipe or repair guide, we've got you covered 💚
Table of Contents
Why Is Your Moccamaster not working?
The following are the 11 most common reasons we’ve found as to why our Moccamaster might not be working and how to fix it:
- Issue 1: Moccamaster Not Getting Hot
- Issue 2: Moccamaster Leaking Water
- Issue 3: Moccamaster Leaking Coffee
- Issue 4: Water Coming Out Of The Arm Slowly
- Issue 5: Filter Basket Overflowing
- Issue 6: It Just Needs A Clean
- Issue 7: It Needs A Descale
- Issue 8: Drip-Stop Mechanism Is Broken
- Issue 9: Coffee Tastes Weak Or Bitter
- Issue 10: Thermal Carafe Not Keeping Coffee Hot
- Issue 11: Power Light Not Coming On
Issue 1: Moccamaster Not Getting Hot
A Moccamaster element is built to heat up water effectively because it’s made of copper, but sometimes it could be the culprit. Or you could have a case of overdue descaling. So, before you pin underheating on the element, it’s best to descale your brewer – if you haven’t already.
Fill the reservoir with water and run your brewer as you would when brewing coffee. If the problem persists, contact Moccamaster or send in your machine for repairs.
Issue 2: Moccamaster Leaking Water
Leaking water is often a result of your machine needing descaling. Descale the brewer using a coffee machine descaler and if the problem continues, send it in for repairs.
Issue 3: Moccamaster Leaking Coffee
If coffee is leaking from your brewer, it could be that your footplate is out of place and causes coffee to trickle on the side of the basket. If you’re using a KBGT or CDGT model, ensure the footplate is firmly in place. For any other model, check that your brew basket is level or that no pieces are missing. If parts are missing, you can purchase replacements from the Moccamaster website.
Issue 4: Water Coming Out Of The Arm Slowly
Mineral buildup clogs up the brewer. This causes water to come out of the arm slowly or stop completely. To unclog your brewer, it’s best to descale the brewer.
Issue 5: Filter Basket Overflowing
An overflowing brew basket can be caused by one of the following:
- Incorrect filter size – too small or big.
- The foot plate is not in place.
- A mechanical problem.
- You’re adding a lot of coffee grounds or too fine grounds in your filter.
Usually, basket overflow is a result of a mechanical problem or what you put in the basket. To verify which is the case, follow these steps.
- Remove any filters or coffee grounds from the brew basket.
- Fill the water reservoir with water.
- Turn the machine on.
- If the brew basket doesn’t overflow, then the coffee grind is the culprit. If it does overflow, then it’s a mechanical problem and you should send it in for repairs.
Issue 6: It Just Needs A Clean
Cleaning your brew will remove any organic material and coffee oil build-up. If you notice an accumulation of organic ‘slime’ in your reservoir or thermal carafe, then it’s time for a clean-up. Follow these steps to clean your brewer.
- Mix the coffee cleaning powder with 32 oz (950ml) of water.
- Pour the solution into the water reservoir.
- Run the solution through the brewer as you would when brewing coffee.
- Run three more cycles using clean water.
To clean the inside of your thermal carafe, put a scoop of the cleaning powder in and fill it with hot water. Let it sit overnight. By morning it should be clean, if not repeat the process.
Issue 7: It Needs A Descale
After a while, minerals in your water accumulate in your Moccamaster’s brewing element, forming scale. The scale slows down the flow of water or stops it completely. You might also notice that your coffee doesn’t taste as good as it used to, or it’s not as hot as you like it. A good rule of thumb is to descale your brewer every 100 brew cycles, or when you finish a box of 100 filters. Here’s how to descale your brewer.
- Purchase a coffee machine descaler.
- Pour the powder into 32oz (950ml) of water. Stir until dissolved.
- Add the solution to the water reservoir.
- Run the brew cycle as you would when brewing coffee.
- When the brew cycle is complete, discard the solution.
- Refill the reservoir with clean water and run it through again.
- Repeat the process two more times.
NOTE: Don’t use vinegar as a descaling agent. It’s not powerful enough to break down all the mineral content and can leave a long-drawn-out odor in your future brews – which can be really unpleasant.
Issue 8: Drip-Stop Mechanism Is Broken
It’s possible for the drip-stop mechanism to become loose after several brews and for the brew basket to drop. Or maybe you accidentally knocked the filter out of the container, causing the spring to move. There are various techniques to fix the drip-stop mechanism depending on the mode of your brewer.
Here’s how to fix the manual drip-stop brew basket.
- Buy a drip-stop replacement kit.
- Using a screwdriver, gently remove the arm with the steel spring.
- Take out the arm with the rubber gasket.
- Slide the slider out.
- Insert the rubber gasket in the basket with the flat rubber side pointed towards the basket.
- Slide the slider onto the basket with the large lip pointed down or toward the top of the brew basket.
- Insert the arm with the steel spring. Push it into place with a bit of force.
Follow these steps to fix the automatic drip-stop brew basket.
- Turn the brew basket upside down.
- Gently lift the arm.
- Remove the old spring and place the new one.
- Place the arm back on top and gently force it into place.
If you prefer to watch a guided step-by-step tutorial, check out this video by Moccamaster USA on how to repair your Moccamaster brew basket.
Issue 9: Coffee Tastes Weak Or Bitter
If you grind your coffee too fine, then your brewer will over-extract, which results in a bitter-tasting coffee. If you grind too coarsely or unevenly, the contact time between the water and the coffee will be limited, resulting in under-extraction and a weak coffee.
To get a tasty cup of coffee brew after the brew, grind your beans to a medium coarse grind. This texture resembles that of coarse sand or sea salt. It’s also best to use the correct coffee-to-water ratio – for every 2 tablespoons of ground coffee, pour 6oz (177ml) of water.
Issue 10: Thermal Carafe Not Keeping Coffee Hot
Excess air within your thermal carafe can cool down your coffee if you brew half a carafe. To keep your coffee hot, brew a full carafe to retain the heat of the flask.
Issue 11: Power Light Not Coming On
There are various reasons why the power light is not coming on. Here are some of the reasons
- The carafe might be out of place.
- The water reservoir is empty.
- Mineral build-up.
Depending on the model you’re using, ensure that:
- The carafe is placed firmly against the button at the base of the brewer.
- You’ve added water to the water reservoir.
- You’ve descaled your brewer after you’ve gone through a box of 100 filters.
When you encounter a problem with your Moccamaster, you might think your investment went down the drain. Anything, but! It’s possible to use your machine and brew the best cup of coffee as you used to if you follow a few simple steps. These include verifying the following.
- Ensure you’re using the correct grind size
- Descale your machine after every 100 brews.
- Check that the spring of your drip-stop mechanism is still in place.
- Send it in for repairs if DIY doesn’t do the trick.