20 appears in digital display of dishwasher
Error code 20 = drain fault. Check whether the dishwasher contains water. If it does, a blockage is the most likely cause. If it appears empty, there may be a sensor or pump issue – call an engineer.
Error code 20 on a John Lewis JLBIDW1200 dishwasher (manufactured by Neff) indicates a problem draining the water. This error may apply to other Neff dishwasher models using the same error code system.
Is There Water in the Dishwasher?
In most cases, a drain fault should be obvious without an error code – the dishwasher will be visibly full of water. It is also possible that it has only partially drained, in which case water may be hidden beneath the main pull-out filter in the base of the machine, directly under the lower spray arm.
If the error code 20 is showing but there is no water inside the dishwasher, the fault may be with the system that detects water presence rather than an actual drain blockage. In this situation, a qualified engineer should be called to investigate. See: book an appliance repair engineer.
How to Remove Water From a Dishwasher
Draining a dishwasher that is full of water is awkward. The most effective method is to disconnect the drain hose at the back and lower it into a bowl or bucket – but this requires pulling the dishwasher out, which is difficult when it contains water. The added weight of the water also increases the risk of damaging the floor surface.
The practical alternative is to ladle the water out. Remove the lower basket and use a suitable vessel to scoop out as much water as possible. Once most of the standing water is gone, there will still be several pints remaining underneath the main filter in the base. Pull the filter out to access this. Using large absorbent towels to soak up the remaining water at this stage is effective.
Possible Causes and What to Check
Once the water has been removed, the cause needs to be identified. The most likely cause is a blockage somewhere in the drain system. A failed pump is also possible but less common.
The following checks are worth carrying out before calling an engineer:
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Check the drain hose connection under the sink. If the dishwasher drains via a spigot on the sink U-bend, disconnect the drain hose and inspect the inside of the plastic spigot and the connection on the U-bend for obstructions.
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Remove and inspect the main base filter. Pull out the large filter under the lower spray arm and carefully check the channel leading into the drain pump beneath it for any obstruction. Common culprits are bottle caps, small bones, and fragments of broken glass.
Large sharp fragments of broken glassware – particularly wine glasses – can get under the filter if it was not seated correctly at any point. Do not probe inside the filter housing with bare fingers. Use a tool or wear protective gloves.
If these checks find nothing, the investigation moves to whether the pump has a power supply or connection fault, or has failed internally. Dishwashers are difficult to work on – there is no back panel to remove, and most internal parts are only accessible by removing the lid, side panels, and kick strip. Do not attempt to turn a dishwasher upside down. If not confident in stripping the machine down, call an engineer at this point.
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Frequently Asked Questions
What does error code 20 mean on a John Lewis JLBIDW dishwasher?
Error code 20 indicates a drain fault – the dishwasher has been unable to drain the water within the expected time. In most cases the machine will be visibly full of water. A blockage in the drain hose or filter area is the most common cause. If the machine appears empty but the code is still showing, there may be a fault with the water detection system rather than an actual blockage.
How do I get the water out of a dishwasher showing error code 20?
Remove the lower basket and ladle or scoop out as much water as possible. Once the main standing water is removed, pull out the base filter to access the water remaining underneath. Large towels are useful for absorbing the last of the water. If possible, disconnecting the drain hose at the back and lowering it into a bucket will drain additional water from the system.
What causes a dishwasher not to drain?
The most common cause is a blockage – either in the drain hose connection, the base filter, or the channel leading to the drain pump. Bottle caps, small bones, and broken glass are frequent culprits. A failed drain pump is also possible but less common. Check accessible areas first before concluding the pump has failed.
4 Comments
Grouped into 3 comment threads.
1 reply Hi, The black plastic spigot mentioned above is loose and falls out causing a blockage and error 20. Do you know what is the purpose of the spigot and if any damage will be done using the dishwasher without the spigot. Thanks, Tony
0 replies It's very unusual for a brand new dishwasher to be faulty. Make sure it isn't anything to do with the plumbing. If the drain hose is fitted onto a u-bend connection that's been blanked off then the dishwasher won't be able to pump out won't drain after newly connected to plumbing The pump should be pretty obvious when it runs. They are usually fairly noisy on dishwashers. The only sounds a dishwasher make are the gushing of the water entering the machine, the whooshing of the water being sprayed around in the dishwasher, and then the pumping out of the water which is a similar sound to that which a washing machine makes when its pump first starts up.
It’s very unusual for a brand new dishwasher to be faulty. Make sure it isn’t anything to do with the plumbing. If the drain hose is fitted onto a u-bend connection that’s been blanked off then the dishwasher won’t be able to pump out won’t drain after newly connected to plumbing
The pump should be pretty obvious when it runs. They are usually fairly noisy on dishwashers. The only sounds a dishwasher make are the gushing of the water entering the machine, the whooshing of the water being sprayed around in the dishwasher, and then the pumping out of the water which is a similar sound to that which a washing machine makes when its pump first starts up.
0 replies I had the error on the very first time I used the dishwasher. Error 20. I can not hear the pump running but as it's new I am not sure what it should sound like.
I had the error on the very first time I used the dishwasher. Error 20. I can not hear the pump running but as it’s new I am not sure what it should sound like.
Hi, The black plastic spigot mentioned above is loose and falls out causing a blockage and error 20. Do you know what is the purpose of the spigot and if any damage will be done using the dishwasher without the spigot.
Thanks, Tony
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Hello Tony, do you mean the spigot on the U bend under the sink that the drain hose connects to? That’s the spigot I refer to.