The clean water tank on my wet-dry vacuum leaks while it's docked
Home Nura guide — category: Robot Vacuum & Mop Combos
Diagnosis
A clean water tank that leaks while the machine is charging usually comes down to a worn or out-of-place seal or cap, or a cracked tank. Take the tank off the dock, dry everything and check the seals and look for cracks before charging again.
Possible causes
- Worn, shifted or dirty cap or valve seal — water seeps out around the cap or the outlet valve.
- Tank not fully seated on the dock — water runs out through the connector instead of feeding the brush.
- Cracked or warped tank — water leaks along a fine line, often after a knock or from using water that was too hot.
- Tank overfilled or filled with a foaming cleaner — pressure and suds push water out through the vent holes.
- Outlet valve clogged with mineral scale or residue — it no longer closes fully and drips even when the machine isn't in use.
What to do
- 1Turn the machine off, unplug the charging dock and wipe up any water around the electrical contacts before you do anything else.
- 2Remove the tank, empty it completely and dry it; only put the machine back on the dock once the contacts and the dock are dry.
- 3Inspect the cap and valve seal, wipe them with a soft cloth and press them back flat into their seat.
- 4Hold the tank up to the light to look for cracks, then test it filled over a sink without tilting it.
- 5Fill it with cold or lukewarm water only, up to the max line, and use no foaming product other than the one the manufacturer recommends.
- 6If the seal is damaged or the tank is cracked, order the original part; don't use glue on the water tank of an electrical appliance.
Repair or replace?
If the tank is cracked and the part is no longer sold, or water has gotten into the dock or the electronics, the machine is no longer safe to use. Replacing the whole unit is then smarter than a makeshift repair.
If you're replacing it
Robot Vacuum & Mop Combos: the picks from our buying guide
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Best overall
Dreame X50 Ultra Complete
A claimed 20,000 Pa of suction, an extending mop and side brush, 175°F (80°C) mop washing, and it climbs thresholds up to 2.4 in (6 cm).
Photo: © Dreame
- View on Amazon →
Best value
Dreame L40 Ultra
A full dock with 150°F (65°C) mop washing, warm-air drying and an extending mop, at a more affordable tier.
Photo: © Dreame
- View on Amazon →
Best for large hard floors
Roborock Qrevo Curv 2 Flow
Its SpiraFlow roller is fed clean water and scraped continuously, effective on sticky spills; it also supports Matter.
Photo: © Roborock
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Other common problems in this category
These issues affect the same type of appliance — each one comes with a diagnosis and the steps to take.
Frequently asked questions
Check the manufacturer's warranty first: how long it lasts and what it covers vary by brand and model, so read the terms for yours and keep your proof of purchase. If you bought it new in the EU, a two-year legal guarantee also applies (Directive (EU) 2019/771), covering defects present at delivery, whenever they first show up.
If you're still within the seller's return window, a return or exchange is usually the fastest fix. After that, go through the manufacturer's support team: it handles warranty claims and can often repair the unit even after the warranty has run out. Either way, keep your proof of purchase.
Our public methodology lowers the Nura Score /10 of any model in our Robot Vacuum & Mop Combos guide whose recurring failures show up in owner reviews. A model that breaks down too often never makes it to the top, whatever the brand.
Generally, yes, if you stick to routine maintenance: cleaning, replacing a gasket, recalibrating. Irreversible changes to the hardware are what can cause problems, so read your warranty terms before you open anything up. Anything the manufacturer's manual walks you through is the safe zone.
Your proof of purchase, the exact model name and a record of the symptom: photos, a short video, the sound it makes and any error code. Note when the problem started and what you've already tried. With all that in hand, support can pin down the problem much faster.