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7 Common Keurig K-Duo Plus Problems: Causes & Fixes

Is your beloved Keurig K-Duo Plus brewing up more issues than perfect cups? Don’t despair. In this post, we’ll dive deep into the world of Keurig K-Duo problems (7 to be exact). We’ll also look at the potential causes behind those lackluster lattes and crummy cappuccinos.

Of course, we’ll also brew up a potful of solutions to get your coffee machine back on track. So, grab your favorite mug and get comfy. It’s time to troubleshoot.

K-Duo Plus Problem #1: The Machine Is Making Lukewarm Coffee

Ah, the dreaded lukewarm brew. This is one of the most common Keurig K-Duo Plus problems, and it leaves your coffee feeling more like an underwhelming bath than a morning pick-me-up. But there’s no need to resort to instant coffee just yet.


  • Low water temperature: This can be caused by mineral buildup in the heating element, a faulty thermostat, or using the wrong water temperature setting.
  • Clogged water lines: Scale and mineral deposits can restrict water flow, impacting heating efficiency.
  • Incorrect brewing size selection: Choosing a larger carafe setting for a single cup can result in a diluted, cooler brew.


  • Descale regularly: Follow Keurig’s descaling instructions using a vinegar solution or Keurig-approved descaler every 3 to 6 months. Ultimately, this depends on the hardness of the water you’re using for your coffee pot.
  • Check the thermostat: If descaling doesn’t fix it, consult Keurig support about thermostat issues.
  • Choose the right size: Stick to the recommended brewing size for your desired amount of coffee.

Bonus Tip: One smart way to reduce mineral buildup and improve the taste of your coffee cup is to use filtered water for your brews.

K-Duo Plus Problem #2: Leaky Lid

Sometimes, you may encounter a leaking lid, which can turn your coffee ritual into a messy affair. If your Keurig K-Duo Plus has this annoying problem, it’ll waste your time, water, and coffee.

Thankfully, you don’t have to let rogue drips dampen your caffeine enjoyment.


  • Worn lid seal: Over time, the rubber seal on the lid can wear down, losing its ability to form a tight closure.
  • Misaligned lid: Improper placement or damage to the hinge can create gaps, allowing water to escape.
  • Clogged needle: Coffee grounds or debris buildup can prevent the exit needle from puncturing the K-Cup properly, leading to leaks.


  • Replace the lid: If the seal is worn, invest in a new Keurig-branded lid for optimal fit and performance.
  • Check the hinge: Ensure the lid is aligned correctly and the hinge mechanism functions smoothly.
  • Clean the exit needle: Regularly remove and clean the K-Cup holder and needle with warm water (you may also use mild soap or put them in the dishwasher) to prevent clogs.

K-Duo Plus Problem #3: Can’t Turn it On

Imagine pressing the brew button with anticipation, only to be met by a silent machine. That’s the frustration of a Keurig K-Duo refusing to power on, leaving you with a cold and empty mug.

If you can’t turn your K-Duo Plus on, it’s not because you’re unattractive. Here are some common causes and fixes for one of the most frustrating Keurig K-Duo Plus problems:


  • Faulty power outlet: Is the outlet itself functioning? Sometimes, a loose connection can be the only hurdle.
  • Malfunctioning power cord: Visible damage like fraying or kinks could be signs it’s time for a replacement.
  • Internal malfunction: This could involve a tripped circuit breaker, a blown fuse, or even a more complex hardware failure. 

While troubleshooting these issues might be beyond DIY territory, knowing the possibilities can help you seek professional help.


  • Give it a power reset: Unplug the machine for 60 seconds, then plug it back in and press the power button firmly.
  • Check the outlet: This might seem obvious, but it’s worth plugging another appliance into the same outlet to confirm it’s working properly.
  • Replace the power cord: If the cord shows signs of wear, investing in a Keurig-approved replacement ensures safety and optimal compatibility.
  • Seek expert help: Contacting Keurig support is the best course of action if the previous steps don’t cut it.

RELATED: Baratza Encore Hopper Won’t Install

K-Duo Plus Problem #4: Wacky Water Dispensing

You press brew, eager for a steaming cup of coffee, but only a sputtering gurgle or a measly trickle emerges. When the K-Duo refuses to dispense water properly it can leave you with a dose of disappointment. Luckily, it’s not beyond repair.


  • Clogged water line: Tiny coffee grounds and mineral buildup restrict the water flow, leading to weak or nonexistent output.
  • Airlock: Air bubbles can get trapped in the system, disrupting the smooth flow of water to the brewing chamber.
  • Faulty water pump: If it’s not functioning optimally or clogged itself, delivering water becomes a struggle.


  • Regularly descale and run a cleaning cycle: Use Keurig cleaning pods or a vinegar solution to clean the brewing chamber and water lines.
  • Prime the water pump: If airlocks are the issue, consult your Keurig manual for specific priming instructions. This helps remove air bubbles and improves flow.
  • Replace the water pump: Lastly, consider replacing the water pump to restore optimal water flow.
Keurig® K-Duo Plus™ Single Serve & Carafe Coffee Maker
  • BREW A CUP AND A CARAFE: Use both ground coffee and K-Cup pods.
  • STRONG BREW: Brew a stronger, more intense single cup and carafe.
  • MULTIPLE BREW SIZES: Brew a 6, 8, 10, or 12-cup carafe and a 6, 8, 10, or 12 oz. cup.
  • MULTI-POSITION 60 oz. WATER RESERVOIR: Can be positioned to the right, left, or along the back of the brewer to optimize counter space.
  • 12-CUP THERMAL CARAFE: Included with your brewer and keeps coffee warm for up to 2 hours.

K-Duo Plus Problem #5: Showing an Error Message

Your Keurig suddenly becomes cryptic, displaying an error code. This can be confusing, especially if you’re not fluent in Keurig-ese.

Obviously, you don’t want anything keeping you from making a hot cup of coffee (or a refreshing glass of iced coffee) with your Keurig. So, here are the potential culprits:


  • Sensor malfunction: The sensor responsible for monitoring water levels or temperature can send out incorrect information. This can lead to error messages that don’t necessarily reflect the real problem.
  • Empty water reservoir: The machine might be throwing an error code because it doesn’t have enough water to brew.
  • K-Cup pod issues: An incompatible coffee pod, one that’s not inserted properly, or even a damaged one can trigger error messages.


  • Consult the Keurig troubleshooting guide: Each error code has a corresponding explanation and solution in the guide. Match the code to find the specific instructions for your machine.
  • Check the water level: Ensure the water reservoir is filled and securely seated to avoid water-related error messages.
  • Remove and reinsert the K-Cup pod: Sometimes, a simple reseat can fix pod-related issues. Also, make sure the K-Cup is compatible with your Keurig model.

K-Duo Plus Problem #6: Perpetually Preheating

In this situation, you patiently wait for your coffee, but the machine never reaches the brewing stage. It’s perpetually in preheating mode. Most of the time, the culprit could be affecting the heating process itself. 


  • Faulty heating element: A malfunctioning or failing heating element doesn’t let the water reach the desired temperature. This traps your machine in a never-ending preheating cycle.
  • Limescale buildup: Over time, mineral deposits like limescale can accumulate inside your machine, insulating the heating element. 
  • Sensor malfunction: If the sensor misreads the water temperature—thinking it’s not hot enough even when it is—it can trigger the preheating cycle to continue indefinitely.


  • Clean and descale: Regularly descaling your machine with Keurig’s descaling solution removes limescale buildup.
  • Unplug and reset: Unplug the machine for 30 minutes, allowing it to cool completely. Then, plug it back in and restart it. This can clear any temporary glitches.
  • Contact support: If all else fails and you suspect that the issue is complex, it’s best to leave it to the experts.

K-Duo Plus Problem #7: Gritty Coffee

Did you take a sip of your coffee, expecting a smooth, delicious flavor, only to be met by the unwelcome crunch of a coffee ground? This unpleasant surprise can ruin your entire coffee experience and leave you wondering what went wrong.


  • Bent filter: If the paper filter is bent or creased, it can’t sit flush against the brewing head, allowing water and grounds to bypass it.
  • Torn filter: A hole or tear in the filter creates a direct path for grounds to escape into your coffee.
  • Internal malfunction: Damage to the brewing chamber, exit needle, or other components can leave openings that allow grounds to bypass the intended flow path. 


  • Inspect and fix the filter: Use a fresh, unbent filter of the correct size for your Keurig model. Plus, you should ensure it sits flush against the brewing head.
  • Reach out to customer service: If you suspect internal damage, contact Keurig support for professional diagnosis and repair.

Remember that using a damaged machine can make things worse, so it’s best not to risk it if simple fixes don’t solve the problem.

The Final Scoop

Trouble with a machine that isn’t working, lukewarm coffee, or unwelcome coffee grounds in your cup? Hopefully, this guide helps you tackle any Keurig K-Duo Plus problems that come your way.

We covered power problems, water flow issues, error messages, and more.

By recognizing potential causes, you can use targeted solutions to restore your coffee maker’s glory and make all those mouthwatering coffee shop drinks in the comfort of your home.

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