Washing machine drain blocked? Plus: proper connection

Signs of a blocked washing machine drain

• The washing machine doesn't pump out or drains slowly and displays an error code.
• Water comes out of the standpipe (the open pipe where the drain hose hangs) when the machine pumps.
• Water comes up in a floor drain or in the kitchen sink when the washing machine drains.
• You hear gurgling in the drain (see drain gurgling).

Step 1: is it the machine or the drain?

If the machine doesn't pump at all (you don't hear the pump or it only hums), the problem is more likely with the machine itself. If it does pump, but the water comes back out of the standpipe or into a gully, the blockage is in the drain.

Step 2: clean the pump filter

Almost every washing machine has a fluff or pump filter, usually behind a flap at the bottom left or bottom right on the front. Fluff, hair, coins and buttons collect there.

1. Unplug from the socket and let the machine cool down if it has washed on a hot cycle.
2. Lay down towels and have a shallow tray ready: more water will come out than you think. Many machines have a small emergency drain hose next to the filter.
3. Unscrew the filter slowly, let the water drain away, remove the debris and rinse the filter clean.
4. Screw the filter back in firmly and check after the next wash that it stays dry.

Step 3: the drain hose

Check the hose isn't kinked or crushed behind the machine. Remove it from the standpipe or disconnect it from the trap and check for debris. Flush it through over a bucket or in the shower.

Step 4: the standpipe or trap

If the hose goes into a standpipe, there's a trap underneath, sometimes hidden in the wall or floor. If water you pour into the standpipe drains slowly, the blockage is there or further along. If the trap is accessible, unscrew it over a bucket and clean it. If it's not accessible, you can carefully use a hand snake. Don't use chemical drain cleaner: it damages rubber and pipes and is dangerous for anyone working on the drain afterwards. Also read blocked drain: clear yourself or call.

Prevention

• Clean the pump filter regularly; your machine's manual indicates how often.
• Empty the pockets of clothing before it goes into the machine.
• Wash very fluffy textiles or pet-hair blankets in a laundry bag, or brush them out first.
• Use the recommended amount of detergent; too much soap can cause deposits in the drain.

Connecting a washing machine: what should you watch out for?

Connecting a washing machine is perfectly doable for the handy DIYer. Always follow the manufacturer's installation manual. The basics:

• Remove transport bolts. A new machine has bolts at the back that secure the drum during transport. These must be removed before you use the machine.
• Water connection. Connect the supply hose to a washing machine tap. A tap with a built-in aerator and non-return valve prevents water from the machine flowing back into the drinking water supply. Tighten the coupling hand-tight and check for leaks.
• Drain. Hang the drain hose with the supplied bracket in the standpipe so it can't jump out, or connect it to a trap with a connection nipple. Don't insert the hose too deep into the standpipe; maintain the height specified in the manual.
• Level. Adjust the feet so the machine stands straight and stable. This prevents vibration and movement during spinning.
• Electrical. Use an earthed socket and preferably no extension lead or multi-socket adapter.

Dishwasher blocked: water not draining

Does water remain at the bottom of the dishwasher after the programme, or does it give an error message about the drain? Then the problem is almost always in one of these four places. First switch off the dishwasher and unplug it.

• The filter at the bottom. Unscrew the mesh or cylinder filter and rinse it clean under the tap. Food residue and grease are the most common cause.
• The drain pump. Under the filter there's often a flap for the pump. If there's a piece of glass, a pip or a label there, the pump won't run properly. Remove it carefully.
• The drain hose. Check that the hose under the worktop is not kinked or compressed, for example by items in the cupboard.
• The kitchen sink trap. The dishwasher usually drains via the kitchen sink trap. If that's blocked, the dishwasher can't drain either. If the sink itself also drains poorly, clean the trap first. You can read more about this in kitchen drain or sink blocked.

If the water still does not drain away after these steps, or if both the kitchen sink and dishwasher are draining poorly, the blockage is probably deeper in the drain pipe. We will then clear it.

Connecting a dishwasher: what to look out for?

• Water connection usually to a cold water tap under the worktop, for example via a tap with an extra branch. Many dishwashers have a supply hose with built-in leak protection.
• Drain via a hose connection on the kitchen sink trap. Let the drain hose run upwards under the worktop first before it goes to the trap, so dirty water from the sink doesn't flow back into the dishwasher. The manual gives the correct height.
• Don't kink or pinch anything when you slide the dishwasher into the cabinet.
• Test for leaks. Run a first programme and check under the worktop that everything stays dry.

Costs and approach if the filter isn't the cause

If the pump filter is clean and water still flows back or over the edge of the standpipe, then the problem is in the drain itself. A washing machine pumps away a lot of water in a short time; a pipe that is only slightly narrowed by lint and soap residue cannot keep up. We unblock the standpipe and the pipe behind it with a spring and then flush it through.

Sometimes the drain itself is too narrow or runs too flat. We often see this when the washing machine has been moved later to a loft or utility room. Then a wider drain or a standpipe with its own trap is the permanent solution.

If the drain needs to be modified or extended, that's a separate job with materials. Feel free to send a photo of the connection and we'll tell you in advance what's needed.