my braava m6 isn't spraying any water when it mops, it's just dragging a dry pad.

Diagnosis

The Braava Jet M6 employs a pressurized pump system to force water through a narrow aperture at the front of the chassis. When the robot drags a dry pad, the failure typically stems from one of three issues: an airlock in the internal pump, a mineral buildup (calcification) blocking the spray nozzle, or a failure in the tank-to-robot seal. If the pump is running (you hear a rhythmic humming or clicking) but no water emerges, the nozzle is likely obstructed by hard water deposits. If you hear no sound from the pump at all, the robot may not be detecting the tank. This happens when the tank isn't fully seated or the electrical contact pins are obstructed by residue. To confirm the cause, remove the tank and observe the spray nozzle; if you see a white, crusty residue around the hole, you are dealing with a mineral blockage. If the tank is leaking from the bottom, the rubber gasket in the tank cap has likely perished or shifted, preventing the pump from creating the necessary vacuum to pull water.

How to Fix It

Follow these precise steps to clear the system and restore water flow:

1. Reseat the Tank: Lift the tank completely out. Inspect the gold contact points on the bottom of the tank and the corresponding pins on the robot. Wipe them with a dry microfiber cloth to ensure a clean electrical connection.
2. Check the Seal: Open the tank cap. Ensure the rubber O-ring is seated flat and is not twisted or cracked. Close the cap firmly until it clicks; a loose cap prevents the vacuum seal required for the pump to operate.
3. The "Prime" Technique: Fill the tank with lukewarm water. Before inserting it, shake the tank vigorously for 10 seconds to break any surface tension air bubbles. Insert the tank and press down firmly until you feel a distinct mechanical click.
4. Manual Nozzle Clear: Use a sewing needle or a very thin acupuncture needle. Gently insert it into the spray nozzle hole at the front of the robot to break through any calcium carbonate crystals. Do not push the needle deeper than 2mm to avoid puncturing the internal tubing.
5. Test Cycle: Place the robot on a hard surface without the cleaning pad attached. Start a "Clean" cycle. Listen for the pump's humming sound and watch for the fine mist spray. Only attach the pad once the spray is confirmed.

If That Didn't Work

• Vinegar Flush: Fill the tank with a 50/50 mixture of distilled white vinegar and warm water. Let the robot run for 15 minutes. The acetic acid in the vinegar will dissolve internal calcium deposits that a needle cannot reach. After the cycle, run one more cycle with plain distilled water to clear the vinegar scent.
• Hard Reset: Perform a power cycle to reset the pump logic. Hold the "Clean" button for 20 seconds until the light ring flashes. Turn the robot off and on again. This can sometimes clear "phantom" errors where the robot thinks the tank is empty when it is actually full.
• Check the Pump Sound: Place your ear near the front of the robot. If you hear a loud, grinding noise rather than a hum, the internal pump motor has likely failed or a piece of debris is jammed in the impeller. This requires a chassis replacement as the pump is not a user-serviceable part.
• Tank Replacement: If the tank has been dropped, the plastic housing can develop microscopic cracks. This allows air to leak in, breaking the vacuum. Try a replacement tank (Part #4440220) to rule out a structural leak.

Heads Up

• Water Quality: Never use tap water if you live in a hard-water area. Use only distilled or demineralized water to prevent nozzle clogs.
• Chemical Warning: Do not use bleach, ammonia, or abrasive cleaners in the tank. These chemicals can degrade the internal rubber seals and permanently damage the pump.
• Storage Tip: If you plan to leave the robot unused for more than two weeks, empty the tank and let the nozzle air dry to prevent mold growth or mineral solidification.
• Pad Saturation: Ensure you are using genuine Braava Jet M6 pads. Third-party pads are often too thick, which can either block the spray or absorb the water too quickly, making it seem like the robot isn't spraying.