Keurig · Coffee Maker Moderate

All Lights Blinking — internal water flow or sensor fault

When all indicator lights flash simultaneously, the brewer has detected an internal fault — typically a clog, air lock, or thermal sensor problem preventing a normal brew cycle. Common across K-Classic, K-Mini, K-Slim and K-Elite.

Keep using it?
Yes, with caution
DIY difficulty
Moderate
Typical cost
$10-15
Verified against
keurig.com ↗

The fix

Keurig Descaling Solution

Internal air lock or scale clog blocking a normal brew cycle

$10-15 easy difficulty 45 min (descale cycle)

Diagnose first: Try the power-cycle and needle-clean steps first — they're free. Reach for descaling solution only if the flashing persists after a reset and needle clean; that pattern points to scale, not a hardware failure.

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Didn't resolve it? Next suspect: Keurig needle cleaning tool / maintenance kit ($6-10)

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How to fix it

  1. Power off and unplug for 5 minutes to reset the control board
  2. Remove the reservoir, empty, and refill with fresh water; reseat firmly
  3. Lift the handle and clean the entrance and exit needles with a paper clip
  4. Run several water-only brew cycles to purge air
  5. If still flashing, perform a descale with Keurig solution
  6. Burp the pump: invert the unit over a sink and tap firmly on the bottom for 30 seconds to dislodge air or scale, then run a water cycle
  7. If lights still flash after descale and burping, the pump or control board has failed

Why it happens

Typical signs: All buttons/lights flashing together · Brewer unresponsive to button presses · No water pumping · Brewer powers on but won't complete a cycle

  • Air lock in the pump Pump cannot prime after reservoir was run dry
  • Scale clog in needle or internal lines Mineral buildup blocking flow
  • Stuck or failed thermal switch Overtemperature lockout has tripped
  • Failed pump Vibratory solenoid pump no longer moves water

More Keurig coffee maker codes

Add Water Add Water Light — reservoir low or sensor fault Auto Off Auto Off — power-save shutdown Brewer Needs Reset Brewer Needs Reset — control board lockup Brew Interrupted Brew Interrupted — cycle aborted mid-brew Descale Light Descale Light — mineral buildup detected Drip Tray Full Drip Tray Full — empty drip tray

All Keurig codes → All coffee maker codes →

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: keurig.com.