Bunn Coffee Maker Slow Drip or Slow Brew Problem SOLVED

Mike C
Written By Mike C

I've been writing about coffee and espresso machines for 3 years. My goal is to provide you with helpful content that you can trust based on my own personal experiences, information from manufacturers, and tips and tricks I've gathered from other coffee and espresso machine users.

I may get commissions for purchases made through links in this post.

Why Your Bunn Coffee Maker Is Dripping Slowly And Taking A Long Time Brew

If your Bunn coffee maker is dripping slowly, it needs to be cleaned. This could be due to a clogged sprayhead or excess limescale. Keep reading to learn more about what causes a Bunn coffee maker to slow drip and what you can do to fix it.

What Causes A Bunn Coffee Maker To Drip Slowly?

If you have not been following the recommended cleaning schedule for your Bunn coffee maker, there are two reasons why it may be dripping slowly.

Cause #1: Clogged Sprayhead holes

The sprayhead is a part on the underside of the top of your Bunn coffee maker. You can find it by removing the brew funnel. It is an important piece that helps to regulate water flow into the funnel. If there are any blockages in the spray head holes, then your Bunn coffee maker will drip slow instead of at the expected rate. Blockages can be formed by tiny debris particles or from residue left by the water.

Cause #2: Excess Limescale Buildup In Tank And Tubes

The water used to brew your coffee contains minerals. The level of minerals in your water will be determined by where you live. Some areas have what is known as “hard water” which is higher in mineral content. Over time, these minerals cause limescale buildup inside your Bunn coffee maker. While not toxic, this can impact the coffee’s taste and temperature. It can also negatively impact water flow which can cause your Bunn coffee maker to drip slow. Descaling, also known as deliming, is the name of the deep cleaning process that removes these minerals.

How To Unclog Sprayhead Holes To Fix Slow Drip

You’ll need a toothpick, the Bunn deliming tool, soft cloth and dish soap. Then follow these steps on how to clean a Bunn coffee maker sprayhead:

  1. Switch the tank to OFF. Unplug the unit from the wall. If it was recently used, let it cool for two hours.
  2. Remove the funnel. Use your fingers to unscrew the sprayhead.
  3. Insert the deliming tool into the sprayhead tube. Leave about 2 inches of the tool out of the tube. Slide the deliming tool in and out of the tube 5 or 6 times. Twist, turn, and use some force when pushing in the tool. This will remove any mineral buildup from inside the tube.
  4. Reinsert the funnel into the machine.
  5. Pour a carafe full of fresh water into the unit, leaving the lid open when done.
  6. Place the empty carafe under the funnel. Close the lid. Water will start to flow.
  7. Take the sprayhead. Use a toothpick to clear any mineral deposits you can see in the holes.
  8. Clean the sprayhead with a soft, damp cloth and gentle dish soap. Rinse thoroughly.
  9. Discard the water from the carafe and place it back under the funnel.
  10. Remove the brew funnel. Screw the sprayhead back in. Return the funnel to the unit.
  11. Plug in the machine and switch the tank power button to the ON position.
  12. After 15 minutes, the water in the water reservoir will have reached brew temperature. Your machine is ready for use.
How To Clean Bunn Sprayhead

How To Remove Limescale Buildup To Fix Slow Drip

You will need to find the Bunn deliming tool that came with your machine or order a replacement in order to complete this. You will also need to decide if you want to use vinegar or a commercial descaling solution.

Can You Descale A Bunn Coffee Maker With Vinegar?

If you look in your user manual, you will see that Bunn’s descaling instructions use vinegar. If you have some around and you are comfortable with that, go for it. Other manufacturers will advise against using vinegar. White vinegar contains 5-8% acetic acid and apple cider vinegar has 5-6%. This type of acid can wear down metal and cause leaks. Vinegar is also less effective than other cleaners at removing oils left by used coffee beans. Plus, it may leave a lingering taste or odor which may make your drink unpleasant.

Instead, I think the best way to clean your Bunn is with one of the below cleaners. They have safe and effective types of acids and they are odorless too and won’t impact the taste of your coffee.

Bunn Coffee Maker Descaling Solutions

Essential Values Universal Descaling Solution
  • Best-value descaler compatible with all coffee makers
  • Uses gentle and odorless citric acid
  • Made in the USA

Essential Values has a citric acid solution that is both odorless and powerful. Each bottle is good for two uses. A two pack will provide four doses. That’s a year supply if you descale your machine every three months. 

Impresa Universal Descaler (2 Pack)
  • Best-value descaler compatible with all coffee makers
  • Uses gentle citric and sulfamic acids
  • Made in the USA

The Impresa descaler is a top selling coffee machine descaler. It uses citric and sulfamic acids. Both are gentle on metal and aluminum. A pack has two bottles, enough for four total uses.

How To Descale Bunn Coffee Makers

Once you have your descaling solution and the Bunn deliming tool, follow these simple steps on how to clean a bunn coffee maker to get rid of limescale buildup.

  1. Slide the brew funnel into the funnel rails. Place the carafe under.
  2. Open the water fill lid, and then:
    • If you are using vinegar, add 32 fl oz of undiluted white vinegar into the top of the machine
    • If you are using a descaling solution, follow the instructions on the packaging to prepare the solution-water mixture in a container. Then pour it into the top of the machine
  3. Close the lid. Flip the side tank switch on. Allow the vinegar or solution to stay in the reservoir for at least two hours. During this time it will mix and heat with the water.
  4. After two hours, flip the switch on the tank to the OFF position. Unplug the unit. Let it sit for at 30 minutes to cool down.
  5. Remove the brew funnel. Unscrew the sprayhead.
  6. Insert all but one and a quarter inches of the deliming tool into the sprayhead tube. Pull the tube back and forth five times. This will help dislodge any buildup.
  7. Replace the sprayhead and then the brew funnel.
  8. Now you need to rinse out the vinegar or solution. To do this, fill the carafe with fresh water only, pour it into the machine and brew. Place the carafe under the funnel.
  9. When done, discard the contents of the carafe. Rinse it thoroughly.
  10. Repeat step 8 three more times. If you used vinegar, you may need to repeat this more than three times to get rid of any lingering odor.
How To Descale To Fix Bunn Coffee Maker Slow Drip

Amazon Item Images and Prices Last update on 2024-05-08 / Affiliate links / Images from Amazon Product Advertising API

Leave a Comment