What Does Error Code 30 Mean?

This error code indicates that the dishwasher is leaking – or that the device designed to detect a leak has triggered. In the base of most dishwashers there is a float mechanism and microswitch. If water gets into the base of the machine, the float rises, the switch activates, and the anti-flood device halts the cycle to prevent further water damage.

Why Is Finding the Leak Difficult?

Dishwashers are generally difficult to access internally. There is no back panel to remove for a quick visual inspection. While a lid can be taken off the top, this only reveals a sealed stainless steel tank and a few external hoses – not the internal components most likely to be leaking.

To access the base and components where water has collected, the dishwasher typically needs to be stripped down. On many models this involves removing the lid, the kick strip at the front, and both side panels to reach the parts crammed into a space no higher than around 6 inches in the base.

It may be worth a quick visual check around accessible hose connections for obvious signs of a leak, but a thorough diagnosis requires significant disassembly. Unless prepared to undertake this, booking a qualified engineer is the practical course of action.

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:

1. 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.
2. 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.

Broken glass hazard.

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.

Frequently Asked Questions

What Causes Error Code 10?

The dishwasher detects that water is not getting inside, but does not identify the specific reason. Possible causes range from straightforward to more involved:

• A kinked or blocked fill hose
• The water supply tap not turned on fully
• A faulty water inlet valve
• A fault in the water level detection system

The diagnostic approach is the same as for a washing machine not filling. Although the linked guide covers washing machines, the principle of checking all the basics first applies equally to dishwashers: machine won’t fill with water.

If these checks do not identify the cause, a qualified engineer will be needed to investigate further.

What E10 Means

The E10 error is a timeout code. The dishwasher’s control system allows a fixed time for each fill and drain stage. If the correct water level is not detected within the fill time limit, or if the machine has not fully emptied within the drain time limit, E10 is displayed and the cycle aborts.

Checking for a Fill Fault

1. Confirm the water supply tap is fully open.

   The tap supplying the dishwasher fill hose must be fully open. Quarter-turn lever taps can appear fully open but be partially seized internally – caked with lime or mineral deposits inside, or with a cracked plastic lever that looks open but is not. If in doubt, turn the tap fully and check again.

2. Check the fill hose for kinks.

   A kinked fill hose restricts water flow significantly. This is most likely if the dishwasher has recently been moved or reinstalled. Gently pull the machine forward and check the hose runs smoothly without sharp bends.

3. Check the water flow at the tap.

   Self-tapping saddle clamp taps (the type that pierce a small hole in the copper pipe) often provide a restricted flow – particularly on older fittings where the pierced hole is small or partially blocked with scale. If one of these taps is fitted, replacing it with a proper isolation valve may significantly improve flow rate. Hot water taps are particularly prone to scaling inside.

4. Check water pressure is adequate.

   If water pressure throughout the property is low, the dishwasher may not fill within the programmed time limit. See our guide on low water pressure and appliances.

Checking for a Drain Fault

Dishwasher drain faults are more difficult to diagnose and access than washing machine drain faults due to the way dishwashers are designed internally. Start with the checks that can be done without disassembly:

• 
  Clean the dishwasher filter. Most dishwashers have a removable filter assembly in the base of the wash cabinet. Remove and rinse it under running water. Fine debris, glass fragments, and food residue can accumulate here and restrict flow to the pump. This is the most common and most accessible cause of drain problems.
• 
  Check the drain hose routing. The drain hose must form a high loop or connect to a standpipe at a sufficient height to prevent siphoning – where water drains back into the machine after the pump stops. If the drain hose hangs low without a loop, water may be siphoning back, triggering the drain timeout on the next cycle.
• 
  If the filter is clear and hose routing is correct – consider an engineer. A blocked or failed pump, a blocked pump chamber, or a control fault causing the drain signal to not register are the remaining causes. Accessing the dishwasher pump typically requires removing panels and working in a confined space. These repairs are better handled by a qualified engineer.

Related Guides

Won’t Fill With Water
Detailed fill fault diagnosis for washing machines – much of the same logic applies to dishwasher fill problems.


Won’t Drain Water
Drain fault diagnosis – pump, filter, blockages, and electrical causes explained.


Dishwasher Not Cleaning Properly
Why dishes come out dirty or with residue – detergent, spray arm, and water temperature causes.


Low Water Pressure and Appliances
How low mains pressure affects fill timeouts – and what to do about it.

Frequently Asked Questions