Clear a blocked dishwasher drain safely by checking the filter, hose and sink waste in one session.
DW-01Make the appliance safeSwitch off and unplug the dishwasher at the socket. If it has its own water isolation valve under the sink, turn that off too. Lay old towels on the floor in front of the appliance, as water will spill when you open it.
DW-02Bail out any standing waterOpen the door and check the base for pooled water. Scoop it out with a cup or an old sponge into a bucket. Wear rubber gloves, as the water can be greasy and may smell.
DW-03Remove and clean the filterThe filter sits in the base of the drum, usually a round or oval piece you twist anti-clockwise to release. Lift it out and rinse it under the kitchen tap, picking out any bits of food, glass or labels caught in the mesh. Check the small chamber underneath for debris too before you refit it.
DW-04Check the drain hose for kinks or blockagesGently pull the dishwasher forward from its housing so you can see the drain hose running to the sink cabinet. Look for kinks, tight bends or trapped sections. Disconnect the hose at the sink end over a bucket and check it is clear by running water through it or pushing a bottle brush through.
DW-05Check the sink waste and non-return valveMost dishwashers drain into the kitchen sink waste pipe or a standpipe, often through a small non-return valve that stops dirty water flowing back. If water backs up here, the blockage may be in the sink waste rather than the dishwasher. Clear the sink's own U-bend or waste trap if needed, and check the non-return valve isn't clogged or stuck shut.
DW-06Reassemble and test runRefit the filter, making sure it locks back into place, and reconnect the drain hose at the sink end. Push the dishwasher back gently, checking the hose isn't kinked or trapped underneath. Turn the water and power back on, then run a short rinse cycle and check underneath for leaks.
DW-07Tidy upDry the floor and cabinet with a towel. Bin any food debris or old labels you pulled from the filter. Wipe down the filter housing and door seal while you're there, as this stops the next blockage.