How to Clean a Bunn Coffee Maker

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Bunn coffee makers are used in restaurants and also in homes.
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With a single- or multi-cup Bunn coffee maker, complete routine cleaning with the unit unplugged and run the brew funnel and glass decanter through the top rack of the dishwasher periodically. Clean thermal carafes using a different method.

Routine Cleaning

On a weekly basis, wipe down the machine with a damp cloth after unplugging it and allowing it to cool sufficiently.

Spray Head Lime Removal

Lime deposits often occur because of impurities in the water used in the Bunn coffee maker. Before removing the deposits, unplug the machine from its power source. Detach and clean the spray head at least once every two to four weeks.

  1. Locate the drip or spray head on the underneath of the top part of the machine, just above where the decanter sits when in use.
  2. Detach the spray head from the machine by unscrewing it with your fingertips. Set it on the countertop or in a small dish so you don't lose it.
  3. Insert the probe that came with the coffee maker through the hole made visible after removing the spray head, leaving 2 inches of the probe between your fingers.
  4. Move the probe up and down through the hole about five or six times to remove any crusty deposits.
  5. Examine the spray head closely to verify its holes are clog free. If not, insert the small end of a toothpick carefully into each of the holes to free up or remove deposits. Run cool water through the spray head after removing the deposits. Verify all the buildup is gone before screwing the spray head back into the Bunn coffee maker.


Hold the toothpick straight as you run it through the spray head to avoid breaking off the tip in the holes. If a toothpick breaks off in the spray head, insert a sewing pin to dislodge it, and then rinse with cold water.

Hard Water Cleaning

Clean a Bunn coffee maker once every three months if you have hard water. Hard water leaves calcium and magnesium deposits inside your machine that affect its performance.

  1. Unplug the Bunn coffee maker from its power source.
  2. Verify the brew funnel is in place in the machine, and set the decanter in the unit as if you were going to make coffee.
  3. Add 1 quart of white distilled vinegar to the top of the brewer.
  4. Once the vinegar has stopped flowing through the funnel into the decanter, empty the decanter and set it back in place.
  5. Plug the coffee maker back into its power source and leave it alone for two hours. For Velocity machines, set the unit to the Vacation switch
  6. Unplug the machine again, leaving the funnel and decanter in it to catch the water you pour through it.
  7. Add a 1 quart of cold water to the machine and let it drain through into the decanter. Empty the decanter and replace it.
  8. Pour a second quart of cold water through the machine. Once the water stops flowing, empty the decanter and set it aside.
  9. Detach the spray head by unscrewing it.
  10. Grasp the machine on the bottom front of the warming plate with one hand and use the second to hold the top of the coffee maker. Empty any remaining fluid into a sink. The water may come from the top of the water tank or from the spray head as you empty it.
  11. Reattach the spray head by screwing it in.
  12. Pour 6 to 8 more quarts of water through the unit with the decanter and brew funnel in place. Empty the decanter as it fills.
  13. Complete a taste test on the water coming from the brewer. If it still tastes of vinegar, continue rinsing water through the coffee maker until it does not have a vinegary taste.

Clean Thermal Carafe

To clean a thermal carafe, insert 2 tablespoons of a powdered dishwasher detergent inside a brew filter placed in the funnel and pour one carafe of water into the machine. Turn the machine on to let hot water into the carafe. Discard brew filter when complete. Allow the decanter to sit for 10 to 15 minutes with the detergent-laden water before cleaning inside it with a soft-bristle bottle brush to remove coffee stains. Rinse thoroughly with cold water before using. Clean the carafe lid after removing the brew-through valve with a liquid alkaline-based detergent. Rinse thoroughly and reinstall.


Omit the brew filter and coffee to use the machine to make hot water for tea. If you have a Trifecta machine, it uses a different cleaning method.


Laurie Brenner

Laurie Brenner

As a native Californian, artist, journalist and published author, Laurie Brenner began writing professionally in 1975. She has written for newspapers, magazines, online publications and sites. Brenner graduated from San Diego's Coleman College.